But the Steed sisters said they always knew that marriage was a future they dreaded. Their prophet, Warren Jeffs, assigned wives to men without asking for consent.
Gloria said this scared her, "because I knew that I'd have to marry a man that I didn't even know."
Ada said she was terrified.
"I always worried about that I would have a creep as a husband," she said. "I always wanted a husband that was the kind to help you."
"All the men down there are jerks, and I wouldn't want to marry any of them," Gloria said. "They're pompous asses. ... The men up here, women are down here; they're peons. 'Do what I say, do what I say, the father rules.'"
Elissa Wall is a cousin of the Steeds who has written a book about her escape from the sect. When she was 14, Warren Jeffs forced her to marry her first cousin. So she knew why her cousins distrust men.
"Men were in charge of us," Wall said. "They were the only way we were going to get to Heaven. We had to love them no matter what. ... We had to share them with other women. ... We had to submit. We had to obey. And through it all, we had to hold them on a pedestal and believe that they were, in an essence, a god in our lives."
As they settled into their new home, the girls held onto fragments of their past. Within the FLDS, everything -- even a simple game of cards -- was based on the bonds of kinship. Six-year-old Nellie called one game "the memory game." It was the FLDS version of Go Fish -- the story of their family in miniature. Instead of matching numbers, Nellie tried finding pairs of her father posing with one of his 38 children.
"Do you have Marrilyn and father?" Nellie said.
"Nope, go fish," her sister Suzanne said.
More than three months had gone by with no word from their father. They still had no idea where he was.
Nellie said they all missed him. She said also that she was worried that she'd never see the rest of her family again.
"We're considered apostates and wicked now that we're out here," she said.
School would be one big difference between then and now.
Instead of studying math and science, Gloria Steed spent her days at school copying Warren Jeffs' proverbs. His image was on every notebook.
When she was writing them, she said, she believed it.
"Well, they were just lying to us," Gloria said.
These days, Gloria was free to study what interested her. So she copied from the encyclopedia into what she called her "body book."
"I'm just barely on AIDS," she said. "It's a terrible disease that they haven't found a cure for."
Other things Gloria and her peers had never heard of included Ronald Reagan and the Electoral College. They were taught that Warren Jeffs was President of the United States.
"Oh, he's a country singer!" Gloria said.
Santa Claus? No clue.
Gloria was told he was supposed to have a magical sleigh and visited all the children in the world.
"Well, he didn't visit us!" Gloria said.
Despite the steep learning curve, it had been an exciting four months of revelations. The girls had never been measured for bras before, and makeup had always been a forbidden temptation.
Suzanne wanted to help support the family, so her cousin Elissa Wall hired her as a seamstress at her baby clothes company.
Simply going to work was a radical break from her past.
"I was never, never allowed to walk out of the yard alone," Suzanne said. "That just wasn't done. And I cannot remember walking anywhere without a parent before. I can out here."
A major milestone in the girls' transformation was the day they all decided to cut their hair.
"The hair is such a big part of what makes a woman and what makes you worthy," Elissa Wall said. "When you cut that off, it's releasing that identity and stepping into new and the unknown."
"I want to have bangs and as short as her hair is," Nellie told her stylist.
"That was quite a time for us," Suzanne said. "Knowing that if I met my father today, he would be displeased with me. But also knowing that I am not living to please him anymore. We have to move on in life and leave things behind."
"We weren't allowed to cut our hair, and you were always considered wicked [if you did]," Nellie said.
How did it feel being "wicked" now?
"Oh, it feels really great," Nellie answered.
For her mother, the experience was bittersweet.
"I was going back and forth between my two lives," Suzette Steed said. "This was the closure to the life there and saying, I'm here."
Ada Steed, 11, hadn't heard from her father in five months, and she clung to a photograph of him that hung on her wall in Colorado City.
But she said that if he returned to them, he would make the family go back to the FLDS.
"I wouldn't go there with him," she said. "I don't want to go back into it. Even if it does cost losing Dad, because I want to have a life."
Ada began to cry.
"We're not supposed to be mad at him, but why did he do all that?"
"Why did who do what?" Elissa Wall asked.
Ada's feelings drove her to the ultimate taboo: defacing a photo of Warren Jeffs.
Her mother was less certain she didn't want to go back. Her path to freedom was shadowed by doubt. For the first time, Suzette Steed was making all the choices for her family. She longed for the security of the home she once knew.
The hardest part was the fading hope that her husband would ever return.
If he came back and asked her to come back?
"I would say yes," she said. "I love him a lot."
When told that their mother felt this way, the girls were stunned.
Gloria said she was "terrified."
"She means everything to me, and I'm not so sure I could do it without her," said Marrilyn, 19. "But I know it's up to her. I just hope that whatever happens, we don't go back."
Despite their fears, what they dreaded even more was confronting their mother.
"The only thing they are afraid of is the way it got crazy down there," Suzette Steed said. "If it will go back to how it was before, I don't think they'd have a problem, really. Because they loved it down there."
When asked if she would go back, Gloria said, "Not if I didn't have to."
What if she did have to?
"Then I don't know what I'd do," she said, crying a little.
"The life we have here is incredible," Marrilyn said. "Why would we want to go back to that hell?"
The strain of living in the outside world was pushing Suzette Steed to the breaking point. On the day she started moving her belongings from home, she finally snapped.
"My husband is a 'son of perdition' now," she said. "Do you think I'm OK? No."
Several months later, the Steed daughters' world seemed ever more one of infinite possibility. They were flourishing at school.
"I want to get my ears pierced really bad," Nellie said.
"I've never had a birthday cake on my birthday, so I've always wanted to blow out the candles," Ada said.
Asked how she felt about being damned in the eyes of her friends and family, Gloria said, "I love being damned if this is being damned."
As for their mother, she had just discovered that her husband chose the religion over his family. He would never return to them. Despite the heartbreak, she now knew she did the right thing.
"I have seen these girls blossom into something I didn't even know that they were," she said. "They were hiding themselves down there, their true selves."
Watch the full story on "20/20: Breaking Polygamy" Friday at 10 p.m. ET
Holding Out Help is one of a very few organizations that specialize in helping members of polygamous communities. For information on how to help those breaking free from polygamy, visit Holding Out HELP's website.