Just because you didn't give birth to the child, doesn't mean you can't love them as much as the mom did. (To be honest, if the birth mom really loved and wanted the child, she would of kept it) But my point is that no one has to be blood related in order to have love towards someone. Just like a guy and a girl. They can love each other more than the girl and her brother for example.
They do not love their children less. Media has been making us think this way. They make birth mothers look like better, loving mothers. Fairy tales like "Cinderella" come down on step mothers. It's actually an extremely selfless deed to adopt an unwanted child. In my eyes it's a win win win. You get the child you wanted. You don't go through the pain of pregnancy. And your saving a child from an unloved life. Honestly it would probably be a good thing if we all adopted are children until there were no unloved children left (By none I mean very little). Then we could start popping out babies again. Not saying that we "have" to do this or it's the only "right" way. I'm just saying it seems like a smarter idea. Beside pregnancies would still happen if this went on.
Adopting a child is heroic and noble deed.