Also, how does she usually play--sitting down, or standing up? From 2-3, my DS rarely sat down--he'd just play with whatever toys by standing next to the coffee table. Now he'll sit no problem. Does she have a table that's her height? For sitting or standing? If so, skip the standing xylophone and go for the less expensive table top one.
I bought my DS a little drum set, which he happily played with a lot for 2-3 weeks; now he'll play with it maybe once a month. He'll also play with the band in a box kit (his favorite item is the triangle--the maracas actually freak him out a bit) maybe twice a month, for about 5 minutes each (same w/ the harmonica and recorder)...so, what I'm saying is that once the novelty wears off, don't expect her to play with it very much (if she does, great, but don't expect her to). You can always upgrade when she's older and more committed. =)