Of course they can and of course it's a spectrum, but it's a spectrum of hate. The definition of homophobia is dislike of or prejudice against homosexual people and it has a negative connotation. That last part is so incredibly important. Issues have arisen in society due to homophobia (and other things like racism) but they are NOT homophobic themselves. This distinction needs to be made.

This girl cannot get pregnant from her genetically female friend. That's not prejudice, that's the way things work. Is it fair? Nope. But that's not the point here. You have NO other basis other than your perceived notion that this woman doesn't know what sex between two women looks like. You throw around a word that has great significance without any proof whatsoever. You, and everyone else who likes to throw powerful words around, lessen the true meaning of the word each time it's used in a way in which it was not intended.