The word 'woman' is taken (adult human female). We are not conceding this sex based term to describe the female of the species - used in the same way as mare, sow, hen, doe - to become a gender based term.
The word 'female' is taken (member of the sex class which produces large immotile gametes and has the capacity, in mammals, to bear young).
The word 'lesbian' is taken (female exclusively same sex attracted)
The word 'apple' is taken, the word 'tomato' is taken. Just because they may both look red (or green) and be spherical and have seeds and are fruit and you are fine with both, doesn't mean you can force tomatoes on someone who is allergic to them and insist it's really 'just like' an apple and suggest there is something wrong with her for making a fuss.
Stop it.
The Equality Act 2010 in combination with the GRA gives 'legal' female/male status in most but not all circumstances only to those who hold a GRC (approx 5-6000 people).
There are estimates of 500,000-600,000 trans people in the UK, so roughly half a million plus without a GRC. Without a GRC, they remain their birth sex in law. So the chances of meeting an actual GRC holding 'female'-in-law-with-some-exceptions "lesbian" is less than 1%.
The protected characteristic of gender reassignment was never designed to cover crossdressers.
Here is the Labour peer, Baroness Thornton (and still the Labour peer responsible for Health and Social Care) presenting the Bill to the Lords back in 2010 and explaining precisely who the protected characteristic of gender reassignment - clause 7 - is designed to protect.
"The point I was making is that that is the range of things that could happen for a transsexual person.
However, Clause 7 does not cover transvestites or others who choose temporarily to adopt the appearance of the opposite gender.
While we do not condone anyone being treated badly because of the way in which they present themselves, it would not be appropriate to provide people who present themselves temporarily as of a gender other than their birth gender with the same protection against discrimination that is available to a person with gender dysphoria, who is somebody who has been assigned one gender at birth, but believes that they are of another gender. That is the point—it is what happens to that person that the Bill attempts to address."
Baroness Thornton on Monday 11 January 2010
hansard.parliament.uk/Lords/2010-01-11/debates/10011139000077/EqualityBill?highlight=transvestites#contribution-10011149000003
It is Stonewall who put crossdressers (transvestites) under its trans umbrella alongside and as 'equally trans' as transsexuals.
Stonewall's position of TWAW and TMAM stands in direct contradiction to the intended protection in the EqA for both the protected characteristic of 'sexual orientation' and for 'gender reassignment'.
Can there be an organisation that advocates effectively for both the LGB and the TQ+? Is it impossible to lobby simultaneously for people for whom attraction is solely sex-based and for those whose personal gender identity is the deciding factor?
Surely they need new (maybe portmanteau?) words to describe people who are attracted primarily by gender rather than sex and stop trying to hijack the old ones.
www.theguardian.com/media/mind-your-language/2016/feb/04/english-neologisms-new-words
A couple of males are in a long term relationship. If one announced a new gender identity, would that automatically become a bisexual relationship? And if both, would that then be a lesbian relationship?
Nope. Tomatoes are not and never will be apples...