Being a mother isn't just about being female. Imagine it's possible to go back in time...How many people would put themselves up for this if they could? Who would give concent to being taken from their mother as a newborn and given to Perez H?
The children of Rosemary West? A bit of an extreme example but foster care is full of children from abusive mothers. When it works, the relationship between a mother and her child is very special but I don't buy into the BS that only mothers can love their children/know what's best for them etc. Plenty of people aren't raised by their biological mother and they turn out fine.