(CNN) Ahmed Mohammed Ali has been working to bring his 12-year-old daughter Eman to the United States since she was a toddler.

She finally got her visa last month and the two of them were waiting for the flight that would bring them from Djibouti to the United States on Saturday, when they found out about President Donald Trump's temporary ban on immigrants from seven countries.

"We were in line with the luggage and they told us she can't get on the plane because she has a Yemeni passport," Ali said. "She is a 12-year-old girl. How is she a terrorist?"

Ali and his daughter are just one of the families whose lives have been disrupted by the immigration ban since it was enacted January 27. Here are four of their stories.

Eman Ali, 12, Yemen

Eman Ali just got a visa to come to the United States from Yemen, but is now waiting in Djibouti with her father.

Eman Ali was born in Yemen in 2005, when her pregnant mother went there to help with a family emergency. Eman is the only member of her family who's not an American citizen.

When they were ready to return home to California in 2007, they couldn't because of Eman's immigration status. The family found out Eman wasn't a citizen because her mother hadn't lived in the United States for five years before she was born.

The paperwork for Eman's visa took years, so her mother and sister stayed with her in Yemen while her father worked at a shopping center to support them.

In 2013 they made an agonizing choice.

"I (had) to let my wife and oldest daughter (come) to (the) US and leave my little one with my dad and mom. I had no choice," Ali said. "I couldn't leave my whole family in Yemen."

They thought Eman would join them soon, but it was almost four years before Ali got to make the trip to Djibouti to finalize her visa at the US Embassy there. The United States does not have an embassy in Yemen because of the civil war that has devastated the country.

"We thought that's it, it's the end. The family will be together. Eman was really happy after all those years," Ali said. "And then they come with a new law."

It's too dangerous to send Eman back to Yemen, so they are staying in a Djibouti hotel. It's expensive, and he can't work.

The Alis have joined a class action lawsuit against the immigration policy and have gotten support from US Rep. Jim Costa of California.

Maryam Hani, 6, Iraq

Maryam Hani, age 6, is being treated for leukemia in Egypt

Maryam Hani was diagnosed with leukemia in October by doctors in an Egyptian refugee camp. Her family fled Iraq's Anbar province in December 2014 to escape ISIS.

"After ISIS came to Anbar, they attacked the area and arrested people and killed people," Maryam's mother, Lequaa Jasim, told CNN through a translator. "We decided to find a safe place for the family."

Maryam's father sold his carpentry business and used the money for pay for their dangerous journey to Egypt.

Since they are refugees, they have to pay for Maryam's treatment out of their own pockets.

Refugees also aren't allowed to work, so they are getting by with help from Maryam's grandparents, who are permanent US residents and have lived in Boise, Idaho, since 2014.

Holda Sadeq, Maryam's grandmother, says she would like to go to Egypt to help file for a medical visa that would let Maryam come to the United States. However, she has an Iraqi passport, so she fears she would not be able to return to the country.

"Holda is just learning English. She's concerned that if she gets on a plane and gets detained somewhere, how is she going to communicate," said Drew Lobner, a social worker who's been working with the family since they came to America.

For now, they're waiting and continuing with Maryam's medical treatment.

"She's tired and is still in the hospital and she had chemotherapy last week, and today they will give her some vitamins," Sadeq told CNN on Friday.

Maryam has another big chemotherapy treatment coming up and doctors say they will do everything they can to make sure she's well enough to travel if she gets permission to leave, the family said.

Dilbireen Muhsin, 2, Iraq

2-year-old Dilibreen

Severe burns disfigured little Dilbireen Muhsin's face.

The toddler's family was forced to flee their home to escape the bloodshed brought on by ISIS when they attacked their village in 2014. They're Yazidis, part of a small community living around Mount Sinjar in Iraq.

Dilbireen's family found shelter among other displaced Yazidis in a refugee camp, where Dilbireen was born on January 4, 2015. A year later, around Dilbireen's first birthday, a fire sparked by a malfunctioning gas heater set his crib ablaze. His mother was baking bread outside when her baby's crib went up in flames, and people nearby rushed to his aid.

Dilbireen was severely burned on his face and feet, but a blanket protected the rest of his body from harm.

Dilbireen arrived in the United States last year to receive medical treatment for his severe burns.

While he now lives with a family in Lansing, Michigan, his parents and baby brother are in their native country, Iraq. They're making efforts to be by Dilbireen's side in the United States, but their travel visas were revoked in early January.

President Donald Trump's travel ban now has them concerned that they won't be able to get back to Dilbireen and that he might return to Iraq without additional surgeries to improve the function of his face.

Fatemeh Reshad, 4 months, Iran

A 4-month-old Iranian girl trying to come to the US for life saving heart surgery is denied a visa due to President Trump's travel ban

The travel ban has delayed an Iranian family's plan to bring their daughter to the United States for potentially lifesaving surgery.

Fatemeh and her family received an all-clear to enter the US for critical surgery, N.Y. Gov. Andrew Cuomo announced Friday.

The family was going to fly to Portland, Oregon, where they have relatives, so Fatemeh could get the treatment she needs. They flew to Dubai, but when they arrived, they were rerouted back to Iran and told to reapply for a US visa in 90 days.

Many state and federal officials have intervened on behalf of the family, a Washington, D.C.-based immigration attorney working on the case, Amber Murray told CNN.

Attorneys involved with the case worked with State Department officials to help the family obtain an emergency waiver to navigate around the ban.

Mushkaad Abdi, 4, Somalia

Mushkaad Abdi

Samira Dahir hadn't seen her 4-year-old daughter, Mushkaad, since she was a few months old.

Dahir had just gotten a visa for herself and her two other daughers when Mushkaad was born. She would have had to start the immigration process over if she remained in Somalia, so she decided instead to leave Mushkaad with a family friend and bring her two other daughters to the United States.

Mushkaad had just gotten her visa and was scheduled to fly to Minnesota on Tuesday, but she wasn't allowed on the flight because of the travel ban.

US Senators Al Franken and Amy Klobuchar of Minnesota, and new Homeland Security Secretary John Kelly, made direct pleas to have Mushkaad resettled as a refugee.

She was reunited with her mother and two older sisters Thursday.

"It's been heart-wrenching for Samira and her two older daughters, who have waited to be reunited with Mushkaad since she was an infant," Franken said in a statement. "I'm very pleased that after far too long of a separation this Minnesota family is now together."

At a news conference Friday in Minneapolis, Dahir thanked everyone who helped her reunite with her daughter.

"I'm very happy today that my daughter Mushkaad is home," a tearful Dahir said. "A lot of people had to work to get my daughter."

Earlier this week, Dahir told CNN affiliate WCCO that she and her older daughters, ages 7 and 8, had decorated a room for their sister and had presents waiting for her.

Now Mushkaad will be able to enjoy it.