There is a girl and I know she is Christian but so am I and I kind of like her but I don't know how to bring the whole gay thing up. I think her mom is homophobic but so is my mom and I am gay so I wan't to know how to ask her about it because every time I think of doing it I get nervous.
You might try bringing it up as a hypothetical. Like ask her what she thinks about gay people and see how she reacts. Don't necessarily ask about yourself specifically, just in general.