Anything that doesn't involve the TV. I would prefer an educational tool.

OH! Do you have any books you could get her? If you spent some time reading to her (nothing intense, just a picture book you could read), I'm sure she would love that. I'm a little biased as a teacher...kids should be doing something active or reading. I'm sure I'll think of more ideas though...

my sister has millions of books....i dont wanna give her something she already has. i wanna give her some exciting new toy...

4 year old girls LOVE babies...
Maybe a babydoll with a little mini stroller/babyseat thing...

My niece is 4 and she loves the girly things, makeup, dress up clothes, LOVES disney princesses.

Usually art project supplies are a big hit too. You can get a TON of markers and stuff like that for really cheap this time of year.