I'd probably go with the 7D (better AF than 5d2, although not as good high ISO). If you really want a FF body, the 5d2 is great, but once I got the 5d3 the AF blew me away compared to the 5d2 (important for a wedding), and the high ISO is a good bit better (quality of noise especially) than the 5d2. It's an expensive upgrade, $3500 just for the body and you can't use the EF-S lens on it. If you can push it, the extra $300 for the kit with the 24-105 is a good deal, as it's a very nice & versatile lens. It is only f/4, but with the 5d3 you can make it work fine.
As KreutzerPhotography said, putting your money into good glass, and maybe the 7D is a better way to go. If she wants to go up to the 5d2/5d3 at some time, I'd avoid EF-S lenses, and stick with EF for now. For used lenses, CL can be good (careful to check the glass, including the looking through to make sure there's no fungus), or keh.com I've heard is good as well.