With one and a half Druids under my belt, I second the suggestions already made in this thread! Druids are definitely the most fun class.
As to talents, I will specifically second the idea of going down to Omen of Clarity in the Resto tree. That's 11 points in Resto, but all of them will actually benefit Feral. Furor is particularly useful, though Imp Mark of the Wild was made useful for Feral since I last leveled a Druid, so the decision isn't as clear cut anymore. If respeccing is an option at 50, I would suggest respeccing and ditching those 11 points temporarily so she can buy Mangle, which is absolutely ridiculously OP for leveling in the 50s... but then again if she's always a bear playing with others, maybe the difference won't be huge enough to warrant it.
If she's going to level Feral with this bear plan mentioned, I can come up with a list of gear that spans the 20-50ish range, since the useful pieces are spread out few and far between. I doubt farming instances for specific pieces is all that appealing though. :p There is a pretty crazy weapon that's fairly fast to farm, however, not far into the back door of Gnomeregan. Cooldown clicky is as awesome as it seems. :p
Like you say though, it's her game. I'd probably just not sweat the small stuff and only aim for things like doing each instance once (perhaps once overleveled so you don't need a full group to do it.) Maybe give some BGs a try. Pretty sure Druids are crazy overpowered in WSG 10-19 bracket now, but I don't know how common twinks are which is a definite buzzkill.