I knew that there was no right way to tell my family that I was transgendered - just that some ways were more wrong than others. (Dressing as Marilyn Monroe and bursting from a cake at a birthday was the first I discounted.) To find the least wrong way, I had to rack my memory for any clues, however minor, however old, as to how my family might react - and try to anticipate them.

I'd come out as 'gay' to them aged 18, when someone who'd been at school with me called to say he'd heard "a horrible rumour" that the girl over the road had seen me wearing a dress (imagine!). My parents were aware that I wore makeup around college, but I knew that I couldn't pass off dressing at home as youthful rebellion: panicking, I decided to tell them something before someone else did.

I naively presumed that 'gay' would cover any sexual or gender difference in my parents' minds: after a couple of tough conversations, things had carried on as before. But I came to think (without any real evidence) that they weren't fully aware of my gender issues, believing that they'd dismissed my sixth-form expression as a phase. For years I avoided the subject because I couldn't find the right word: cross-dresser sounded too innocuous (like writing to say I'd taken up the ukulele), transvestite too sexual, and transgender too vague - it would invite further questions rather than clarify who I was.

Coming to define as transsexual meant I'd have to come out again. This would be much harder, as my stock line of "I'm still the same person" wouldn't work so well: in time I'd have a different body, a different voice, and a name different to the one they'd given me.

I discussed it extensively with friends, as well as checking the Transsexual Road Map's page on coming out to parents. A letter seemed best: I handwrote three pages, starting with the present and then explaining my past in the context of my gender issues. Then, I figured, they could digest it and respond when they felt ready. Trembling, I posted it: there was no going back.

I spent the following days contemplating their response. I expected neither ecstasy nor excommunication, but could not guess where between those extremes it would fall. I knew that their expectations for me would be challenged - and most likely exchanged for anxieties. Would they think it was their 'fault'? Fear for my future? Or be ashamed of me?

Days later, I received an email from my father, explaining that although they were struggling to comprehend my decision, time and understanding would enable us to continue to be part of each other's lives. They visited me in Brighton and we had a long, difficult conversation where we discussed all their fears at length: I might regret it (a risk I was no longer unwilling to take); I might not 'pass' (not my primary concern); I might get beaten up (I'd developed strategies against that in Crawley and Manchester).

Eventually, it seemed best to try to talk about something else. "Who am I going to talk to about football?" asked my mother. "Me!" I replied. She was by no means the only person to think of this first. One friend's second question was, "Will you still support Norwich?" To which I said, "No, Ipswich."

Perhaps this was because they'd absorbed some stereotypical ideas about trans women becoming Stepford-esque when living as female. I was surprised that they'd applied this to me - but I was more surprised that on coming out, friends and family might initially see my transition as some sort of 'death'. Carrying on our relationships as normal soon proved that all that was 'dying' was my masculine façade.

Fine: as long as your loved ones can accept that conforming to the expectations around your assigned gender was a 'façade' and carry on 'as normal' - or at least try. Support services for families of transsexual people exist, but remain underfunded and underpublicised: Depend offers information and online discussion forums; the Beaumont Society, originally a support group primarily for heterosexual transvestites and their wives, provides opportunities for trans people and relatives to meet; and Mermaids runs an information line for gender-variant children and their families.

None of these, though, are particularly prominent, and I'm sure that my parents weren't the only ones who didn't know where to find them, turning instead to television documentaries - which often overplay the 'pathetic' in 'sympathetic', or reinforce stereotypes and prejudices handed down through generations as transgenderism became visible during the last century.

Attending the Clare Project for sessions with a gender-specialist counsellor, I saw firsthand how the internalisation of these prejudices affected people - people transitioning in their fifties or sixties because they'd felt too afraid to do so in their youth, in floods of tears because their wives might become estranged, their children (or grandchildren) might disown them, or their elderly parents might die without accepting them. One friend of mine was barred from her mother's funeral, long after coming out to her family. I'm sure she was not the first, and won't be the last, to suffer such rejection.

I'm fortunate enough to be able to negotiate a new 'normality' with my parents: I've asserted my new identity more slowly than with my friends, allowing them time to adjust, and share the news with other relatives, who - having less invested in my gender and public image - have been accepting. For my parents, my 'becoming a woman' has not realised their worst fears (embodied by those Daily Mail columns and cartoons): 'time and understanding' from both sides have indeed allowed us to remain part of each other's lives, thanks to our willingness to respect and share each other's concerns.

I hope that with each generation, more families are able to do the same.

• Juliet Jacques's column appears fortnightly. You are invited to post comments and questions for Juliet below, and are very welcome to share your own experiences.