As a guy, the only form of birth control you can trust is a condom. With other forms of birth control, you are trusting your girl to use them properly. Sometimes that's fine (I was on the pill for many many years and never slipped up) but it's not like that for everyone. You are always better off using birth control that is under your own control.
As for your girl, she should talk with her doctor and make her own decision. I was fine with birth control pills and now have an IUD; other people prefer other options. It's a very personal decision. Be supportive, but let your lady make the decision herself. As Misty pointed out, it's important that she pick a method that works with her lifestyle, personality, and ability to remember things. If a person knows they are not good at remembering medications, then birth control pills may not be the best choice! (I could probably count on one hand the number of BC pills I forgot to take over the course of years -- but that's just me).