Point one.
I'd ask why mermaids changed their advice so rapidly, from watchful waiting (as evidence points to 80% of trans children, actually grow up to identify in their birth sex) to total affirmation and often a medical pathway?
This quote from a mumsnetter discusses this, and links to the mermaids old website;
"From 2009
Active Mermaids members are mainly parents or young people - some of our children are transsexual, some are not. Some of our children have attended the Gender Identity Development Service of the Portman Trust, two of whose clinicians are in an advisory position on our Committee.
Perhaps also it might go some way towards explaining transgender issues in adults, such as transvestism, and transsexualism - each adult transgendered person was once a gender variant child, but please never forget: a gender variant child or teenager will not necessarily grow up to be a transgendered adult.
<a class="break-all" href="//web.archive.org/web/20090626134957/www.mermaidsuk.org.uk/intro.html" rel="nofollow" target="_blank">web.archive.org/web/20090626134957/www.mermaidsuk.org.uk/intro.html
Gender isn't an issue for 3-year-olds: If your son enjoyed dressing in a clown outfit and one day announced that he was a clown, you wouldn't worry that he was going to want to wear nothing but clown suits when he was 12, would you? And even if your son develops a lifelong predilection for dressing in women's clothing, it may interest you to know that most cross-dressing males are heterosexual.
The bottom line: This is nothing to worry about. Announcing that he is a girl is no more significant than our daughter Amy announcing at age 3 that she was Jennifer. Within a year, Amy was again telling people her name was Amy, and within a reasonably short time your son will let go of the "I'm a girl" thing.
Mermaids 2011:
A child becomes aware of its gender identity before or around the age of five years, in many cases as early as 2 or 3 years of age. In most people their gender identity is the same as their sex, i.e. a woman or girl feels she is female and a man or boy feels he is male, but in a few people their gender identity and their sex do not match, and this can cause problems.
Interesting change in tone over those two years (and much fancier website) along with new aims:
Offer support to parents, families, carers and others.
Raise awareness about gender issues amongst professionals (e.g. teachers, doctors, social services. etc.,) and the general public Campaign for the recognition of this issue and an increase in professional services. "