This is the TV show that kicked off the others, I think? First aired in 2011 and repeated in 2012.
en.wikipedia.org/wiki/My_Transsexual_Summer
(Featuring Fox Fisher, who went on to found ‘My Genderation’ with ‘Owl’, and published pro trans books aimed at children)
Fox features on the Mermaids Retreat promo video they tried to hide.
From the wiki link
In April 2010, non-profit organisation Trans Media Watch published a study called "How Transgender People Experience the Media", which found that there is "an endemic problem with negative and inaccurate representations [of transgender people in British media stories], and observed that this leads to considerable real-life suffering".[5]
in an effort to improve this situation, Trans Media Watch drafted and published a memorandum of understanding for media companies: signatories of the memorandum agree to "work toward… increasing positive, well-informed representations of transgender people in the media."[10] In March 2011, Channel 4 became the first company to sign the memorandum.[11] "Our editorial independence always come first; but it is part of our remit to reflect the diversity of the UK", said Cosgrove.[11]
After signing, Channel 4 engaged journalist/activist Paris Lees of Trans Media Watch to be a production consultant for the show; Lees served as consultant for the duration of production.[12]
BBC3 aired ‘Transsexual Teen, Beauty Queen’ (about Susie Green’s child) in 2012.
Up until this point, IIRC, trans on telly was mostly older male transitioner types.
But ‘I am Leo’ is the biggie, because it went out on CBBC, so was expressly aimed at 7-16 year olds.