C.P.
Hmm.. That's a tough one. We also have a 3.5 year old, but unlike your daughter, the toys he asks for are things he plays with ALL DAY long. So we don't mind buying more and more Thomas the train, for example, or his latest obsession is with Star Wars... Because he's home all day and plays with his toys all the time. I think I agree with you... if she's not playing with the WEbkinz, why buy them?
I think if I were in your shoes, I'd try introducing her to something new. Crafts are great, but she also should be playing with things that will allow her to act out stories and pretend play... Does she have a kitchen? Does she play with dolls? I'm not sure what girls this age are into, but I bet if you put up a new post, you'll get loads of good suggestions.