Spermicide. Sponges. Cervical cap ( spermicide). Diaphragm ( spermicide). Female condoms.

Don't use a female condom with a male condom! They can rub together and cause breakage. For the same reason, don't use two male condoms together. Spermicide and sponges do offer more protection than a condom alone. You can use a cervical cap or a diaphragm with a condom, but she would have to go to the doctor to have one fitted. I'm guessing she wouldn't want to do that.

Also, just FYI: When you use a condom, make sure you haven't kept it in a warm place (like your car or wallet) and that you use a little lubricant before you put it on so it won't rub against your penis, which again, can cause breakage.

Ultimately you need to decide if this is the right girl for you. It sounds like you guys have different values and beliefs that are coming up with sex, but probably extend to other things, too. Also, if she does get pregnant, you might wish that you hadn't taken the risk. She might be a wonderful girl who you love very much, but if you guys are really this much at odds about something so important, maybe it would be better to find someone who does share your views.