Believe it or not, there are those out there who think you can't love a child as deeply if they are not "your own" (i.e., biologically related). To those people, I want you to watch this video.
Like every other species, women are capable of loving a child as their own, regardless of their biology. And, as an adoptee myself, I can say a child is capable of feeling the love of a mother who did not give birth to them.
All women can be mothers.