Last year, the Victoria Derbyshire programme met children going through a period of extraordinary change - but what's happened to two of the UK's youngest transgender children since?
Last May, Lily, seven, went to school wearing a skirt and was called by a girl's name for the first time. She was born a boy, and "skirt day" marked her transition to life as a girl.
It seems both she and her classmates took it in their stride. "When I went to school that day, everyone was saying, 'Hi Lily, you look nice in a skirt'. And I was like 'ooh thanks,'" she says.
"It felt a bit natural, but mostly embarrassing because the tights were making me itch a lot. It stopped becoming embarrassing after a while."
Lily - not her real name - had recently begun dressing as a girl in January 2015. "It feels a bit different but mostly the same because I just get on with it like I did when I was a boy," she says.
Find out more
Last year's piece about Lily and Jessica can be found here.
Transgender is a term used to describe a person who doesn't identify as the gender that was assigned to them when they were born - they may wish to be seen as a different gender or no gender at all.
The UK's only centre specialising in gender issues in under 18s is the Tavistock and Portman NHS Trust which has clinics in London and Leeds.
In the last year, 167 children aged 10 or under have been referred to clinics, almost double the number the previous year. They include three children aged three. It's something psychologists there put down to society becoming more accepting.
The other young girl we met last January is Jessica - not her real name - who is now nine. Then she had been going to school as a girl for two months.
When she describes her excitement at getting her ears pierced, she sounds like a typical young girl. "I just wanted to look like a girl, I wanted to do it straight away," she says.
But her parents say her life is starting to get a little difficult.
Her mother Ella explains: "It's been a really good year, school's going really well and now she can get her name changed [to Jessica] legally as we have her dad's permission.
"But she's been having nightmares - that she's going to die a man, she's going to have a beard. She's already started requesting [hormone] blockers."
Her stepfather adds: "The thing with kids is they think it's going to happen instantly, that she's going to wake up and that's it, it's going to have happened."
They think hormones may be responsible and say they hoped for another "straightforward year" before the onset of puberty.
Jessica admits she finds it hard when people forget to treat her as a girl. "I get a bit annoyed and angry as I don't like it and I can't control my temper very well," she says.
She says she's looking forward to the day her gender is no longer an issue. "I'm not going to end up being a boy forever, because I will be a girl and I know that. Sometimes it doesn't feel like that though."
Younger transgender children can receive treatment on the NHS, but at that age it takes the form of counselling and support sessions. Medical intervention isn't considered until they approach puberty, when hormone blockers might be offered.
Blockers delay the physical changes associated with puberty, giving the young person longer to decide if they want to live as a man or a woman. At the age of 16 a patient can then take cross-sex hormones, with full surgery only offered after the age of 18. The estimated cost of gender reassignment surgery on the NHS is around £10,000.
Jay Stewart, director of Gendered Intelligence - an organisation that supports young trans people - says it's common to find life more difficult during puberty. He says a combination of social, psychological and physiological support can help.
"Such difficulties don't affect all trans people, but there is a narrative of young people where their bodies are developing in a way that is not welcome.
"Services, such as schools, must be aware that such visible changes that puberty brings can feel stressful because we know that that will have an impact on the way that we are treated in society."
Lily's parents say she appears to be happy and not yet thinking in depth about the future. But it's also been a big year for her family.
Lily, who had been asking to live as a girl for several years, took control of the pace of change by telling her school she wanted to be known as a girl. "She just ran ahead with it really," her mother Jen says.
The family had numerous meetings with the school to plan the transition. Then on the day she wore a skirt for the first time, Lily's headteacher led the whole school in an assembly focused on accepting differences.
For Jen, it was an emotional time. "It felt like a really important day, an official day where that boy was no more and now we are having a girl."
Lily's nine-year-old brother first noticed she was different when she wanted to buy pink dresses and play with dolls and fairies. But now he says their relationship is "just normal".
They both go to the same primary school - where, he says, everyone is "fine with it now".
"They [other pupils] used to ask me, before we started assembly, 'why does your brother like girls' stuff and things'. And I would say 'because that's how she is'. I'm very proud of what she's gone through, she's doing really well at the moment and no-one's bullying her or anything, so it's fine," he says.
Jessica's home life has seen a big change too.
Her biological parents split up and her mother has been in a relationship with another woman, Alex, since she was a baby. In February 2015, Alex also decided to transition and start living as a man.
"I didn't want to do anything about it until I felt that Jessica and the family were in a more stable place - I thought now was the time I needed to be more true to myself I guess," he explains.
"I've pretty much felt the same as Jessica, but didn't understand or know until I researched what was going on with Jessica. Then, I instantly knew myself."
But the couple do not believe the fact Alex has transitioned shows they have influenced Jessica.
"If it was the other way round and Alex had transitioned first, and then Jessica, then I would think it was an influence," Ella says.
Some people might think this is just a phase, which the children will grow out of. Lily's mother, Jen, says it's hard for people to understand unless they've lived with a child in the same situation.
"This is a medical condition, it's not a choice, it's how they were born. You can hear people who are going through transition at adulthood say that they knew at this early age.
"We're just trying to support our children so they can have longer in their lives being who they want to be," she says.
All names have been changed in this interview. The children, their families and schools gave consent for the interviews to take place.
Tips from Jessica and Lily's parents
- Don't panic, you are not alone. Contact Mermaids who can help you get in touch with support networks. Meeting other parents is invaluable
- Do research - Gires is a great source of information; watching online videos of trans kids, like "I am Leo", is really helpful
- Ask your GP for a referral to the NHS Tavistock Gender Identity Service
- Allow your child to express how they feel and dress in whichever gendered clothes they choose to build self-confidence and to discover who they really are
- Support, love and accept your child for who they are, and help those around you to understand and accept your child too
For more information and support:
Mermaids gives support for children, young people and their families
Tavistock Centre - the only NHS gender identity centre for under 18s.
The Gender Trust gives support to the over 18s.
Gendered Intelligence gives support to young people.
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