This story was originally published on CNN.com in 2015. Kelly Wallace is CNN's digital correspondent and editor-at-large covering family, career and life. Read her other columns and follow her reports at CNN Parents and on Twitter.

(CNN) When Hillary Whittington learned she was having a girl, she and her husband, Jeff, were thrilled. Naturally, the couple started getting ready for the arrival of their first child.

There was the pink and white nursery to finish, dresses and bows to buy.

Like most first-time parents, they thought they had prepared for just about everything. Then, only months after Ryland was born, the Whittingtons realized something wasn't quite right.

When they called out, Ryland didn't respond. Ryland was deaf.

Cochlear implants restored young Ryland's ability to hear, and the Whittingtons thought they had overcome their toughest challenge.

But Ryland had more to share with them, according to the family's incredibly powerful YouTube video , which has been seen more than 7 million times. Their story is also the subject of an equally moving short film "Raising Ryland," which is exclusively being showcased on CNN.com.

Ryland, they learned, is transgender.

Hillary Whittingon and her son, Ryland, who is now 7.

"Transgender" essentially means having the body of one gender and the brain or the mind or the spirit of the opposite gender, said Darlene Tando, a licensed clinical social worker and gender therapist who also appears in "Raising Ryland."

"So being transgender means you have something other than what everyone assumed you were based on how you were born, what body you were born in," said Tando, who also writes a blog about gender issues.

The Whittingtons no longer have a daughter. They have a son.

Ryland: 'When the family dies, I will cut off my hair'

When I asked Hillary Whittington when she knew Ryland was transgender, she said there were a lot of signs.

Ryland would scream "I'm a boy" as soon as he started speaking and showed an aversion to anything feminine, said Hillary, who is working on a book about her family's journey, which will be published by HarperCollins.

Ryland's just a tomboy, thought the Whittingtons, something Hillary could relate to as a former tomboy herself.

"But the difference was Ryland was shameful about it and knew that he kind of had to hide it," said Hillary from her home in San Diego.

"He just picked up really quickly that it wasn't OK for him to really want to be a boy. It was OK for him to do boy things and stuff, but he just learned really quickly that there was a limit to it."

Everything changed the day Ryland announced, "When the family dies, I will cut off my hair so I can be a boy."

Ryland may have only been 5, but the Whittingtons determined that it was time to start listening.

Hillary and Jeff Whittington and their children Ryland, left, and Brynley.

"A lot of times, kids don't say anything, or they keep it hidden, or they modify their behavior based on the wishes of those around them," said Tando, the gender therapist.

But when they start getting feedback from others about how they should dress, which line they should stand in or what activities they should be involved in, they may start speaking up, she said.

"And that's when they may start asserting themselves, 'I am a boy; I am a girl; God made a mistake,' that sort of thing, and then the parents will know there is some distress going on here because the brain gender identify is not matching the birth sex."

The Whittingtons sought help from professionals and experts, and they researched everything they could.

'Do I want a living son or a dead daughter?'

"Do I want a living son or a dead daughter?" Hillary Whittington asks so powerfully in the film. "We were not willing to take that risk," she wrote in her YouTube video.

Family and social acceptance are key factors in the health and well-being of someone who is transgender, explained Tando.

Transgender resources LGBTQ crisis intervention and suicide hotline for : 1-866-488-7386

Confidential counseling via text message: 202-304-1200

More resources at www.thetrevorproject.org

"I think the scary stats we see about transgender people are those who have probably not been affirmed by their families for a very long time or have kept it to themselves for a very long time," she said. "And then the coming out process is more difficult the older they are."

Those "scary stats" don't usually apply to children, like Ryland, who can live as the gender they identify with at an earlier age, according to Tando.

"They've shown over time that kids who have family support like the early intervention, they have a very similar statistic of suicidality and suicidal ideation as the general population," she said. "So the family support is so important."

A gender-affirming approach in which the parents listen to the child is "by far the one that's most likely to have a positive mental health outcome," said Dr. Stephen Rosenthal, a pediatric endocrinologist and medical director of the Child and Adolescent Gender Center at the University of California, San Francisco.

Rosenthal pointed to a 2014 Dutch study, which found that transgender young adults who were given medicine to delay the onset of puberty and were then given hormones corresponding to their gender identity were found to be just as happy and satisfied with their lives, if not happier, than the young adults who didn't identify themselves as transgender.

"That's what this family needs to know," Rosenthal said of the Whittingtons, "what the world needs to know."

'Coming out' to family and friends

After consulting with counselors and experts on transgender issues, the Whittingtons were advised to allow Ryland to transition as soon as possible. So they let him cut his hair and change his room, and they sent out a letter to family and friends telling them that Ryland is a boy and their amazing son.

Ryland credits his parents with letting him be who he wanted to be.

"That was our initial 'coming out' letter," Hillary Whittington said. They wanted to answer questions from family and friends before they asked.

"It's really hard to explain the facts to someone in person especially when you have your child standing there," she added. (Ryland has a sister, Brynley, who turns 3 in a couple of weeks.)

They lost a few friends but learned that the people who stuck with them are the ones who really matter.

Facing judgments, questions and criticisms

When I ask about the judgments, questions and criticisms that the Whittingtons have faced, she said she didn't want to "go there" because "it brings out a lot of pain."

A few minutes later, as she talked about the support they received from Ryland's kindergarten teacher and the rest of the school district, she couldn't really hold back the tears.

"I think for all these parents, the reason why it's so hard," she said, as she apologized for getting emotional, "is because you worry about their safety. It's a safety concern. I think that's why I struggle still. I just hope that we're doing the right thing."

What drives her, she said, is first and foremost protecting Ryland, making his childhood as typical as possible and loving him unconditionally.

After that, she hopes that by being public and vocal about Ryland's story, she can help educate people and provide hope to other families.

"As difficult as this is, the more people will talk about it and share their stories and be willing to risk their privacy ... I think the more we're going to help people understand that this isn't some weird thing," she said.

"It's a lot more common than you even think. It's just that people are afraid to talk about it," she added.

"I just feel the need to talk to these parents and help them get on board with this because the longer you wait, if you let these kids go through the wrong puberty, you are really putting their lives in jeopardy, and that's really why I'm doing this, because I'm trying to really save these kids."

A new calling

Two years into their journey, Hillary said they are still in the "thick of things." They still haven't officially changed the gender on Ryland's birth certificate and the middle name he was given when he was born, she said.

Thankfully, his birth name, Ryland, does not need to be changed. "It's so awesome that it's a gender-neutral name."

Moving forward, there will be more challenges, she concedes, including working with doctors on what to do to block puberty and deciding at which age to start administering cross-hormones.

Beyond that, it really is an individual choice regarding whether a transgender person will change their anatomy. "Some transgender people are very accepting of their bodies that they were born with, and it's really not a source of distress for them, so they don't feel the need to undergo surgical intervention," said Tando.

"Others have a really strong sense of gender dysphoria, and so they feel like they really need to undergo some medical intervention to feel more comfortable in their own skin."

Hillary said they will cross that bridge when they get to it.

"At this point, we don't have any worries other than just to keep his world as happy and normal as we can."

From what you see in the film and the family's YouTube video, Ryland, now a 7-year-old first-grader, seems like a happy and healthy boy. Last year at a diversity breakfast in honor of Harvey Milk, the first openly gay politician to be elected to public office in California, Ryland thanked his mom and dad for "letting me be who I want to be."

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"I'm the happiest I've ever been in my whole life."

Hillary said she now knows what her calling is: fighting for Ryland and kids like him.

"I made a promise to Ryland that I would help and I would do something ,and obviously now that's my new journey," she said.

"I'm not afraid of what people can say because I know that the worst has already been said and really, at the end of the day, I know that ... eventually the naysayers will see that this really is OK and that we are doing the right thing."