Figuring out that he was transgender and making the decision to take hormones to transition his body from female to male was difficult for Jace Martinez. But figuring out how to tell his 5-year-old daughter, he says, was "really a challenge."
So Jace, 23, decided to write a picture book, simply titled "My Mommy Is a Boy."
Written from his daughter Amaya's perspective, the self-published book, intended for an audience of one, explains Jace's feelings and his decision to change his name, wear men's clothes and begin taking testosterone to change the appearance of his body.
"Mommy told me in her heart she always felt like a boy and being a girl always made her sad," he writes in the book. "Mommy likes to wear boy's [sic] clothes and cut her hair really short," reads the text under a magic-marker drawing of a short-haired Jace in a barber's chair. "Sometimes kids ask if she is my Daddy."
Jace lives in Oregon, the home state of Thomas Beatie, a female-to-male transgender man who wrote an article this week in the gay-rights magazine The Advocate explaining his decision to become pregnant. Beatie said he decided to become pregnant after his wife became sick and infertile. He previously had his breasts removed and was taking hormones, but had retained his uterus and female sex organs.
The National Center for Transgender Equality estimates there are some one to three million transgender people living in America. How many of them are parents, however, is unknown.
Explaining the birds and the bees is a challenge for any parent, but transgender individuals have the added difficulty of explaining not just the basics of human sexuality but the complexities as well.
Experts who counsel transgender parents say younger children, like Amaya, tend to adjust to the news of their parent's transition better than teenagers, and the best thing a parent can do is to be open and answer their child's questions.
"Amaya knows she was in my tummy. She is still pretty young and never asks about sex, but I know she will someday," Jace told ABC News.com. "The book says I was unhappy being a girl. She knows that I have girl parts, but I'm taking a shot and it's making me like her dad."
Jace was married to a man and pregnant when she was 19. A year later, when Amaya was one, Jace began his transition toward becoming a man.
"She has always known me as a 'trans man' and has never known me as a feminine person," he says of Amaya. "She still wants to call me mommy. I want her to call me something else and tell her to whisper 'mommy' in public. I want her to call me something other than mommy, but that's what she wants and I don't think I could ask her to stop. I think it would traumatize her. She knows that if she has any questions, she can ask me whenever she wants."
A child who has known his parents as transgender for her entire life will accept it more easily than a child who learns about it when she is older, said Dr. Stephen B. Levine, a psychiatrist who works with transgender parents and the author of "Demystifying Love."
"Will having a transgender parents make a kid crazy? Probably not, especially if the kid learns when he is young," Levine said.
"When children are young, they have an emerging understanding of gender. They label themselves and then begin labeling others. It's much more difficult when a child is a bit older — 9, 10, 11 or a teenager — and has an established sense of gender and then daddy becomes a woman," he said.
"Everybody has screwed-up parents," he said. "Some people's parents are also transgender."
Walter Bockting, a psychologist and coordinator of transgender services at the University of Minnesota's Program in Human Sexuality, said parents need to talk to their children openly and at an age-appropriate level.
"There is not much research on transgender parents. But two studies found children of transgender parents do fine. There is always an adjustment period, especially for older children who know their dad as a man that then becomes a woman."
"When coming out to children, it is always appropriate to do so at an age-appropriate level. When a parent begins transitioning and coming out, it is something of adolescence for them too. They might be taking hormones which not only affect their body but their mood too. It is important for a transgender parent to remember they are a parent first."
Bockting said transgender people often have a lot to deal with when coming out — explaining their transition to friends, navigating a changed relationship with a spouse, facing discrimination at work — that they need to take time to focus on how coming out affects their children.
"As people come out when they are adults, they need attention and affirmation. Sometimes there is a separation when a spouse can't deal with the change, and a marriage cannot adapt. Kids then have to deal with two issues: first their parent's transition and then their parents' divorce," he said.
For parents who transition before they have children or transition when the children are still very young, Bockting recommended parents let them know and not keep it a secret.
"A person does not transition in a vacuum. Other people know that man was formerly a woman, and the kid will eventually find out. It is best not to keep it a secret."
Monica Canfield-Lenfest first learned her father planned to make his outward appearance match his innermost feelings and become a woman when she was 17.
Because of feelings of shame and fears of being teased, many children keep their parent's transition a secret, leading the children to feel isolated and alone, said Canfield-Lenfest, who, as a fellow at Colage, a group that counsels children of gay and transgender parents, is writing the first resource guide for children of transgender parents.
"The biggest thing is a feeling of isolation. My dad came out when I was 17, and I thought I was the only one," she said.
"People have all kinds of reactions. One friend found out his father was about to undergo a transition and his reaction was 'Oh, that's fine, can we make the 2:20 showing of X-Men 2.' Other people are angry. Many have questions right away, and others need to process the information more slowly."
"The best things a parent can do is keep their door open and answer their kids' questions," she said.