Reliable methods of birth control that aren't condoms or the pill?

Keep it in your pants, while she holds her knees together.

If that’s the main reason she doesn’t want to take the pill, she ought to look into other hormonal methods. You change the patch once a week, which seems to me like it would be harder to remember than taking the pill daily, or change the ring once a month (you get a timer to remind you on that one.) There’s also the injectibles. Depo is progestin-only, and you get it every three months. Lunelle is a combined-hormone shot you get every month. The shots are especially reliable, since the only way to screw it up is to not get it in time. They can be fairly pricey, though.

Well, since silentgoldfish is Australian, most of these methods won’t cost a thing.
As for rhythm method, isn’t your gf studying to be a nurse? She should be able to figure it out.

But if it’s just that she doesn’t think she’ll be able to take it. I again, recommend Implanon, lasts 3 years, most effective one on the market.

No, I’m the nurse. My gf just teases me about needing a uni degree to wipe bums :).

Something like the shot does sound best – we’re going to a family planning clinic when she’s researched all she wants.

The lowered sex drive bothers me a little (though the important thing is no babies!). Do you not feel like doing it as much? If someone else initiates it can you still get in the mood?

The side effects of hormonal birth control vary wildly from woman to woman. Some women don’t have any side effects at all. Some women have positive side effects like reduced cramping and lighter periods (or no periods at all). Other women have negative side effects such as weight gain, breakthrough bleeding, headaches, weight gain, loss of libido, increased bleeding, etc. Sometimes the side effects are fairly mild–a little spotting mid-month, a little extra crankiness a day or so a month, being slightly less inclined to initiate sex, etc. Sometimes the side effects are really horrible–heavy bleeding for weeks on end, mood swings that make you look and feel ready for the looney bin, such complete loss of libido that sex actually seems mildly repulsive. You just never know how a woman will respond to a particular hormonal treatment till she takes it.

Some women find an increased libido, spurred on by the reassurance that there is virtually no chance of pregnancy.

Some drop pretty much to zero. No interest in initiating or responding to advances.

And there are other issues you wouldn’t expect: For my wife, her period stopping was the single greatest thing that ever happened to her. For a friend of hers who also tried Depo, having no period made her feel like she wasn’t really a woman anymore. YMMV.