IT would be hard to think of a more macho CV than one listing Royal Marine, firefighter and father.

And Katie has done it all – when she was still living as a man.

The 40-year-old jokes that if she had been born a girl she would have been a tomboy.

In fact until earlier this year she has been living as a man – although since around the age of four she had often felt that she was in the wrong body.

When she just five she started dressing in female clothing in private, and spent part of her time living as a woman in private while she was married, with the support of her then wife.

But over recent years she started feeling that to be true to herself she had to live and identify full time as a woman.

Last year she told her friends, family and her two children that she was transgender and since March she has been living full time as Katie.

When she was little Katie’s family supported her exploring her gender identity, allowing her to experiment with make-up, wear nighties to bed and to dress in girls’ clothes at home.

But when she was around nine she felt her family discouraged her from experimenting.

“I ‘cross dressed’ in secret when I could,” says Katie, who lives in Hampshire.

“When everyone was out I could sit there for a couple of hours looking like I felt then suddenly I’d have to not be like that. I remember crying in bed at night wondering why I wasn’t allowed to wear a nightie anymore.”

Katie says that although she often felt she was female on the inside she enjoyed traditionally male pursuits.

A keen footballer, she also excelled at Sea Cadets and went on to join the Royal Marines. Despite having a small build, again she succeeded.

“People said because of my height and size I'd never make it through Marines training but I did. I always wanted to be the best and achieve as much as I could and the Marines is the elite.”

She passed out as a section commander and went on to serve for six years, including a stint in northern Iraq and southern Turkey. It was a life she loved.

But at the same time, she was living a secret life as a woman.

Katie met her ex-wife shortly before joining the Marines.

“Just before we got engaged I told her about my gender identity,” she says.

“She was really supportive, absolutely brilliant. Sometimes I would sit in the front room as a woman with her, reading magazines and doing our nails together.

“We were ok managing my gender identity, identifying as a man to the outside world, knowing I couldn’t really live as a woman to the world because it would have jeopardised our relationship, my career, everything.

“The question rose early in our relationship of whether I wanted to live as a woman full time but the answer was ‘no’.

“If we didn’t have the fears of how society would have reacted to it the answer might have been different.”

After leaving the Marines, Katie went on to pursue another ambition and became a firefighter for Hampshire Fire and Rescue Service, receiving the Silver Axe at the end of training, awarded to the best recruit.

At this time the couple had the first of their two daughters. They were, Katie says, a very happy, loving family but several years later the marriage ended.

“The separation was mutual,” she says.

“My gender identity was never brought up as a reason for the break up.”

After the separation, Katie began to feel more and more that occasionally dressing and identifying as a woman in private was not good enough.

“I realised you are who you are inside. There’s nothing you can do about that and I shouldn’t be afraid of being who I am inside.”

In January last year Katie decided to tell everyone in her life that she was a transgender woman.

She told her daughters while they were watching TV together.

“There was a man on telly dressed as a woman. It was an opportune moment. I said he might be transgender and added ‘actually that’s how I feel. I feel that I should be a girl.’ I gently started to explain what it was and that it doesn't change me as a person. When they asked about it again I showed them a picture of me as a woman. My youngest said ‘you look really pretty, Dad, you look like a girl,’ and my eldest said ‘you look really old!’.

“I started leaving some of my female clothes out like shoes and some pink pyjamas. They would both walk around in my shoes and try my wig on.”

Katie has regular contact with her eldest daughter and hopes that this will soon be the case with her youngest as well.

“Society doesn’t fully understand transgender,” says Katie.

“It doesn’t understand that my daughters still call me ‘Dad’ because that’s what they know me as. I’m not trying to be their second mum. I am their dad. I’m a parent and that’s a status I will carry through the rest of my life.”

She called a family conference to share news and sent letters to other relatives and friends.

“My ex-wife and I had told my brother way back and he was always brilliant but I was worried about telling my dad.

“None of them were shocked. My dad was like ‘yeah, we knew there was something different because of how you were when you were younger.’ I’d had a real fear of telling him. He has passed away now but he was fantastically supportive.”

One group of people Katie was worried about telling was her colleagues at Hampshire Fire and Rescue, where she works as a fire safety watch manager.

“The fire service is traditionally a very masculine world,” she says.

“I was acutely aware that all of a sudden I was going to challenge the perception that people have of a firefighter.

“I didn’t know what their reaction would be but it was so fantastic that I quickly realised I could transition.

“I can’t speak highly enough about Hampshire Fire and Rescue Service and how supportive they have been, from a corporate and an individual point of view.”

It took Katie until March this year to start living full time as a woman.

“There was a year of me coming to terms with the fact that everyone else was going to be alright with it.”

It has been a bumpy journey. But she knows she is now on the right road.

She says that it is as a transgender parent that she has faced most challenges.

“Everyone felt I was a great person and parent before coming out but now I feel that certain people, including the authorities, are calling that into question and that’s really not OK,” she says.

“This has created a huge hole in my life that my daughters used to fill.

“I have been socially reassigned as a woman,” she says.

“There is medical reassignment where you take medication which I'm going to start soon and I may go on to full surgical reassignment. I'm not going to make that decision until the time comes because it's risky, major surgery. I need to take every day as it comes.

“I am so much happier now. I don't question myself at all now.

I don't question the journey I am taking. I am incredibly at peace with myself.”