03/09/2015 12:17 BST | Updated 02/09/2016 06:59 BST

Boy Meets Girl: The Versatile Actress Rebecca Root Stars in Groundbreaking Comedy

The first thing I notice when I meet Rebecca Root is her smile. Warm, open and friendly, it lights up the room. We meet at Fringe Central 1, in Edinburgh, where she is at the end of her run playing Eden in the award-winning show Trans Scripts. It is not the lightest of topics for a fringe show, but the verbatim piece about the life experiences of transgender women, are the key ingredients to one of the most educational and thought provoking shows at this year's festival.

Her character Eden is very complex and quite aggressive whereas Root is engaged and open. It's as draining a part as anything she's ever done but exhilarating too, in front of a live audience for a month with her fellow actresses, baring their souls day in day out. She says: "The first couple of weeks of the run I had to find a way to negotiate the path in and out of Eden, so to speak, so my prep and my getting out of character has become less stressful as the time has gone on."

Eden is both tough and independent but damaged and vulnerable. Having witnessed the performance of Trans Scripts and watched the screening for BBC2's new comedy Boy Meets Girl, where Root plays the loveable Judy, her versatility as an actress is astonishing. "I'm pleased that you've seen both sides of Rebecca Root because I think few people will get to see that," she adds.

Sitting next to Root, on the low sofa, we chat at length about her groundbreaking role in the first mainstream UK sitcom to cast a transgender actor in a leading transgender role, and her hopes for the show. So what is her part and why does she love it so much? "Judy is adorable, funny, warm, she's a bit inept at times but she's just charming, I'm not saying she's without her complexities but her heart is in the right place."

Judy is a transgender woman in her 40's who meets a younger man, Leo (played by Harry Hepple), in a bar and they hit it off. The couple are on their first date at a restaurant when Judy utters the words: "I was born with a penis." Written by Trans Comedy Award script writer, Elliott Kerrigan, Boy Meets Girl is simply a love story. The fact that Judy is transgender is only one element in a funny and touching romance.

Unlike her character, Root shies away from dating, for self-preservation "who puts themselves in the line of fire of heartbreak." But that's not to say she wouldn't like to. "One day perhaps I will meet someone."

Root grew up in a middle-class, loving family in Surrey. Her parents and two sisters supported her in her desire to act but she found there was no one she could really talk to about how she was feeling at the time. Acting in school plays gave her a way to be female, if only for a short time. "Suddenly I had this creative outlet, I had something that I loved, and something that I could aspire to."

It is clear to see the passion that Root shows for her work, "I care so much I can't tell you, I am so passionate about my craft! I take my craft and my profession very seriously and I do classes and read books and talk to a lot of actors and I watch their performances. I scrutinise what they do and wonder how they do it, I'm like a child again."

Her transition began in 2000 and she recalls that probably the hardest part was making the decision to do it, "I knew what I had to do but I wasn't sure how I could do it. It took me a long time of conversations with doctors and specialists."

She would advise any young person who is struggling with their identity today "to be brave, breathe deep, look at yourself in the mirror and smile, I taught myself to look in the mirror and smile once a day and that way I am guaranteed one smile. But that smile buffers me against all the frowns, glances and the 'what the...' that I still even now occasionally get."

Articulate and informed it is hard to imagine a better ambassador than Root for the transgender community. Does she feel a sense of responsibility in this role ? "In life if you're given an opportunity to share a perspective on life, or society or humanity, it would be churlish not to accept that role, and to try and do good with that

"I do workshops now with youth transgender groups, the NHS and I'm a mentor for young people. I don't necessarily promote myself but if anyone can benefit from it then I will do it."

Rebecca Root will also play a small part in the hugely anticipated The Danish Girl, an autobiographical drama based on one of the first known recipients of sexual reassignment surgery, Lili Elbe, played by Eddie Redmayne.

She is looking forward to the premiere of Boy Meets Girl this week but feels that "it's funny because I'm in a bit of a bubble at the moment, although it is very exciting I'm realistic in that I'll believe it when I see it. I hope the audience like it.

"This is not just my moment, it's Elliott's moment, it's the rest of the superb cast's moment. It is very much an ensemble. But it's also the trans community's moment. I have been contacted on social media by a lot of trans women saying 'I have seen the trailer , it looks great, fingers crossed, thanks for all you are doing'. That means a lot."

With a supporting cast that includes Denise Welch, Lizzie Roper and Nigel Betts, this may just simply be a funny tale of boy meets girl.