Surely it is time to recognise and accept that sex is genetically fixed and unchangeable?
That girl/woman and boy/man refer to specific sexes at specific states in their development.
That it is not possible to change from one to the other, but that it is possible and permissible to present yourself as either.
That nobody can be obliged to behave in a particular gendered manner. Men and women should, for example, be permitted to wear the uniform of the opposite sex (as long as it does not interfere with them carrying out their jobs).
That insisting that you are a woman with XY chromosomes, or a man with XX chromosomes, is Gender Dysphoria, a mental illness on a par with any other body dysphorias, and deserves compassionate treatment.
That appropriate treatment should be available for GD, but that hormonal or surgical treatment should be forbidden before the age of 18. This would include puberty blocking.
That there should be no more stigma to having GD than to having any other mental illness, such as depression or anorexia. And people with GD should not be discriminated against because of their condition.
That the only time 'gender' can be changed retrospectively should be in the case of proven Intersex conditions, when suitably qualified medical professionals agree that it would be in the individual's best interest.