It really seems very simple to me. Posie has two points on which she campaigns:
Men cannot become women and should never be treated in law or by society as if they could.
Medical intervention in minors in the name of "gender identity" is equivalent to child abuse.
Posie's campaigning MO is straightforward:
tell as many people as possible about these two views, regardless of their political persuasions or stances on other issues
Some people think self-ID is a step too far but it's reasonable to treat some transsexual males as women in law with a few caveats. Some people think it's reasonable to medically treat some children but only with gatekeeping, not affirmation. Some people prefer political purity to speaking to anyone. Posie takes a different view. As is her right in a democracy.