PEOPLE spoke with Sharon Shattuck, whose father, Trisha, transitioned from male to female when she was a child

Caitlyn Jenner coming out as transgender, and most recently, her debut on the cover of Vanity Fair brought the topic of gender identity to the forefront of public conversation. But a gender transition doesn’t just impact the person who is transitioning – as evidenced even by the Jenner-Kardashian clan, family members need time to come to terms with it, too. PEOPLE spoke with Sharon Shattuck, 32, the filmmaker behind the upcoming documentary From This Day Forward, whose father, Trisha, 60, transitioned from male to female when she was a child, about her own experience having a transgender parent.

Just like Caitlyn Jenner told her children during her Diane Sawyer interview, my dad told me that she would always be my dad. But to the rest of the world, she’s Trisha.

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When you’re a kid, your parents are just necessary forces in your life. You can’t choose them, or change who they are. When I was a child, my father began her transition from a man to a woman.

Now, I can’t imagine not having that force in my life – it’s an experience that impacted me tremendously, enough so that I recently made a documentary, From This Day Forward, about Trisha, my family and our experiences.

Today, there’s all this great cultural upswell in society when it comes to the trans community – there are these amazing people who are putting the issue out there, and making people realize that the things they say are hurtful.

But in the late ’80s and early ’90s, especially in my small town in Northern Michigan, it wasn’t like that. The whole world has grown and adjusted – and so have I.

Discovering Her

My sister and I discovered this side of our father, then a landscape architect, at a young age. My sister was snooping around my dad’s office (as kids do), and in the trashcan, found two photos stuck together. She pulled them apart and saw a picture of my dad in a dress. She brought them over to my mom (who is 62 today) and asked her ‘Why is Dad dressed like Grandma?’

Rather than trying to hide it, or turning it into some big, shameful, secret, my parents decided to tell us on Christmas morning. Now, I don’t remember the exact year, but it was sometime in the ’80s – we were young. My dad told us that she had a surprise for us, went into her room, and when she came out, she was wearing a dress.

When you’re a kid, you’re open-minded, and therefore, pretty accepting. And really, we didn’t know what our dad wearing a dress meant. So my sister and I thought it was no big deal.

The Long Transition

When my sister and I first found out, Trisha wasn’t living as a woman, but she started the transition soon after. And in total, the whole process took about 10 years.

She had the surgeries, on her nose and the tracheal shave, early on in my life. I really remember her face, swollen up like Homer Simpson, after she had the electrolysis. By the time I was in middle school, she was taking hormones and regularly dressing up.

What was tough for us – and for Trisha – was that she’d sort of flip back and forth. One day, she’d be wearing a dress, and the next; she’d be in worker overalls. She’s really not a very girly person most of the time, and a lot of women aren’t. But for us, it was sometimes like ‘Are you a woman, or ?’

To top it all off, she never really insisted on switching pronouns. Her thing was always that she wanted us to be ready, and for us to figure it out on our own.

It also was sort of muddled by the fact that my parents did want to stay together. When you’re married to a woman who is straight, you don’t really want to tell her that she has to use feminine pronouns when referring to the person who was once her husband.

The Big Move

When I was in fifth grade, my family moved from the suburbs of Chicago to a small town in Northern Michigan. In our new town, there wasn’t a lot of diversity. Growing up there, I don’t think I even knew any LGBTQ people.

Moving at that age is hard regardless of your familial circumstances. You’re just trying to fit in. But it was especially difficult for my sister and I – here we are, trying to fit in, and we have this huge thing that is making us stand out. We didn’t want to talk about it at all.

Luckily for my sister and I, we really didn’t face much discrimination because of our dad, and both made lots of friends.

However, Trisha really confused, and in a lot of cases, put off the older people in town. People would across the street to avoid walking next to her, and some would just completely ignore my parents in public.

I spent the bulk of my teen years trying to hide my dad’s gender identity. When a friend dropped me off at home, and informed me that the ‘town cross dresser’ lived next door to me, I immediately told her, ‘No!’

The morning after one particular sleepover, I was so anxious, trying to strategize how I could get in the car without my dad coming to the door in a dress. My friend’s mom noticed how worried I was, and told me, ‘Sharon, it’s okay. We all know.’ But I just couldn’t admit it then. I just said, ‘Know what?’ I still wasn’t ready to talk about it.

As we got older, we weren’t totally exempt from the judgment Trisha faced, either. In high school, my sister’s math teacher told her, ‘I know what your Dad is, and I don’t approve.’ What was she supposed to say to that? And to make it worse, when she told school administrators, all he got was a slap on the wrist – nothing really happened.

It wasn’t until college that I felt comfortable discussing Trisha with anyone. In high school, my close friends knew, but we didn’t talk about it. And everyone knew that there was a ‘cross dresser’ in town, because back then, in our small town, no one even knew what being transgender was.

But in college, I met a lot of LGBT people who were my age, who became my friends. A few months into my freshman year, I was sitting with a group of these friends in a house. Everyone in the group was gay, so I had wanted to tell them the truth about my family for a while. Sitting on the floor, I finally just thought ‘I should just tell them this.’ It was weird for me not to.

And I did, and they were so accepting. That’s what made me start to feel okay telling people.

When you have a parent who is LGBT, you completely fly under the radar: If you don’t tell people, they won’t know. Really, it gives you a sense of power in telling people. You’ll be in a room, and you’ll hear someone crack a joke about a guy wearing dress. You can be a person that they know that has a transgender family member – and that’s the kind of thing that changes people’s minds.

Staying Together

The thing that I think makes my family’s situation really unique, especially when compared with Caitlyn Jenner’s path, is that my parents stayed together. It wasn’t always a sure thing – I remember a few times during my childhood, my parents would sit my sister and I down and tell us that they were getting a divorce. But they could never go through with it.

I think for my mom, a pathologist, the biggest hurdle was that she is attracted to men. I don’t think everyone could stay with someone who was transitioning. It’s a lot – you don’t have that masculine energy present anymore. I don’t know if I could do it.

Trisha also never had surgery on her genitalia, or sexual reassignment surgery, so she and my mom are still able to have a sexual relationship.

My parents are still attracted to each other physically, so my mom was always like, ‘I think we could be friends, if you had the surgery – but we couldn’t be married.’

I figure Trisha would have gone through with the surgery if it weren’t for my mom, and the sake of their relationship. But after talking to her more before I started making my film, I learned that it was really more about her own fears.

‘I hate the sight of blood,’ she said to me. ‘I’m terrified of surgery.’

The surgery on her nose was almost the last straw – she lost a lot of blood. Reassignment surgery would obviously be extremely invasive, and back in the ’80s, I’m sure it was much riskier.

A ‘Normal’ Family

Growing up, all I wanted was to be from a ‘normal’ family.

But now, I’m grateful that my family is different. It’s made me more compassionate toward other people’s differences.

I can’t imagine how hard it’s been for Caitlyn, to go through such a personal experience as such a high-profile person. Seeing photos of all those paparazzi waiting outside the clinic where she was having the tracheal shave surgery, I just thought, ‘Oh my god, how horrible would that be?’

When you’re transitioning, you’re in such a raw and vulnerable place. I can’t imagine having to do that with the rest of the world watching.

Trisha never watches TV, so when I told her about Caitlyn coming out as trans, she was a bit clueless – but happy. Having someone that high-profile coming out as transgender, it’s changing our culture – it’s great.

Shattuck works with Colage and the Family Equality Council, two groups for the children of LGBTQ parents.