I live very close to Niagara Falls!
If she is going to be around Buffalo she simply has to go to Duff's and try some of their food! Especially their wings, which they are famous for. If she does like wings, remember to tell her that Duff's actually does make their hot sauce HOT, so to order a level down from what she usually gets to be safe.
There's the river, the aquarium, the casino, a wax museum on the Canadian side (and another one I think, can't remember what it is though).
Not sure how long of a drive away it is, but it's not like two hours or even an hour I think. The Galleria is a huge mall and she might want to go there if she feels like shopping!