Currently though there are many more areas which need biological sex to be recognised due to the many ways women and girls are treated as lesser, property or as objects.
Absolutely. And one way to deal with these horrific oppressions and violations of women might be to attempt to dismantle the system of differentiation in which women are constructed as Other, and as objects of oppression. Not an overnight task, though.
I don't see how we can do without biological definitions any more than we can ignore race, it is recognised to protect the opressed from the would be oppressors.
Racial difference was also constructed via assertions of biological difference, at least in the modern world. There's some very objectionable material that passed for science in earlier centuries which purported to have found biological explanations for the supposed inferiority of Africans, for example. Shocking stuff, and rightly rejected these days by right-thinking people.
As I'm sure you know adjustable that quote of de beauvoir is often repeated by trans activists to suggest a male can "become" a woman.
I know, and I think it's often taken out of context and misinterpreted. I would like to see a good analysis of how Beauvoir's use of Hegelian existentialism might apply to trans experiences, since I think this is missing from that argument. (Sorry for pseudo-intellectual waffly bollocks
.)
For the record, I'm in favour of trans rights, but I agree that there are some serious difficulties that need to be addressed in how those rights are conferred in society, and I'm particularly aware of the need to preserve everyone's safety. However, I'm not sure that insisting on biological definitions of 'woman' is necessarily helpful because of the possible unintended consequences of that course of action (i.e. underscoring the biological basis for oppression of women).
What definition of woman includes all natal and tran's women and excludes all natal and trans men?
I don't think there is one, but that's because I don't think the definition of 'woman' is immutable.