How's this any different than a one night stand? Or put up for adoption? Or a child of a broken relationship where one or both adults don't want her or don't want her enough to pay support or visit?
Oh, I know. She has one parent who dearly loves her. She needs to get over herself and be thankful what what she has.
That's the stupidest reaction that could have been anticipated.
A child deserves a father and a mother.
A child of a one night stand, or a child who is abandoned by her father or a child who is put up for adoption have similar problems.
The need for a father and a mother is a real and legitimate human need and it is immoral for someone to deliberately deprive someone of a whole home.
Morally, it isn't. Those are wrong, too. That's the point.