Biological the mother is the woman who gives birth, same applies legally, until a parental order passes through the courts or a child is legally adopted.
If a woman has difficulty with that word I suggest she doesn't get pregnant, to have her own children or someone else's.
Surrogacy, being an exploitative industry and banned in many countries for that reason, I seek to protect women who wish to be surrogate mothers for financial, emotional or self-motivated reasons.
For the babies that are born from surrogacy I will do what I can to have surrogacy restricted further in the UK (or at least for the laws not to be further relaxed) to protect a newborn from trauma, because, in my view, no child should be born expressly for the purpose of being removed from their mother, again the woman who gave birth.
(The exception being where a child is at risk from harm or neglect by the mother. If the mother posed a danger to a child then the child should be somewhere where they are safe and one hopes, loved. Someone in my extended family keeps having babies but she does not care for them so they are repeatedly placed in care. Not surrogacy but the mother knows she is giving birth to a child expressly for the child to be removed, alt most immediately after birth. If she stopped getting pregnant the babies wouldn't be traumatised. If the babies stayed with her, they would be traumatised further.)
You can think I am vindictive, disinterested in self-reflection and enormously selfish. You are entitled to hold that view.
Surrogacy isn't all fluffy happy families. If you want to believe it is, I would suggest you are narrow minded and could perhaps research the darker side of it a bit more then see if you feel the same way. I am entitled to hold that view.
Ultimately it doesn't matter what you or I think and say on here Ov9. What matters are the laws around surrogacy and people not breaking those laws and people not being harmed by those laws. This? This is just a discussion.