@Binkytheslug - I would have absolutely no problem with your friend using the female only spaces. I would guess that, before she had the bottom surgery, but had had the hormone treatment, the last thing she'd have wanted is to have someone spot that she still had her penis - plus I believe the hormone treatment can shrink it anyway.
She would simply want to use the facilities as unobtrusively as possible - which is vastly different to a predatory man using self-ID as an excuse to enter female only spaces and ogle women or make them uncomfortable by being blatant about displaying their male biology.
In some ways, self-ID and the unintended consequences for female only spaces and women's safety will also harm those genuinely trans women - people who are living full time as women and either have had, or are in the process of getting the treatment to transition fully - my guess is that these people just want to get on with living their lives, without conflict or hassle - and self-ID could cause them to be hassled more, whilst trying to simply exist.
I used to have a friend who had fully transitioned to female - the only reason I say 'used to' is that, since I moved, we have fallen out of touch - and I was entirely comfortable with using her chosen name and pronouns. I would have had no problem sharing a changing room or the loos with her because I know she respected the other women using those facilities. The last thing she would have wanted is to upset someone, or make them uncomfortable.
If self-ID comes in, a male medical practitioner's feeling that they are female would override the needs of women like @AmazingGrace16, and she could be accused of transphobia and literal violence for not wanting a male-bodied person anywhere near her antenatal care, her birth, or her post natal care. This is male violence against women, and I cannot understand any woman who would say this is OK.
@AmazingGrace16 - you are really amazing, and I hope the rest of your pregnancy and the birth go well. 