It has been said pretty well on this thread already, but i just wanted to inject my girl perspective:
I was on the pill for about 3 years. I hated it. It was effective, however, i often times forgot to take it and when i doubled up on the pills, i would get sick and throw them back up. It wouldn't even have a chance to get into my system.
I was so happy when the Patch came out. I have been using it for over 4 years and am VERY happy with it. I have lost weight from it, my skin is still clear from it, not a bad period, mood swings.. well, i am moody to begin with
Other than that, it is great beacuse i don't have to remember to take a pill every day.
But, with the BCP, if she takes it on time, everyday, she will be fine. use a condom for the first month she is on it so her body can become use to it before you stop with the condom.
Good luck.