Simple jewelry is a good idea. A necklace or a bracelet, or even earrings. Or else stationery, but that would have to be some good ones, like a cute notebook or pencil/pen. In my opinion, I dont think that stuffed toys are very good because they really don't have much use, so unless you know she really likes stuffed toys, stick with jewelry or stationery.
you cna buy a teddy bear or neckles to her!! You need to tell me how old is she?? if she is 15 years old you can buy a flower and a teddy bear or a neckles to her!! If she is you sister you can have dinner with her!! If she is your younger sister you can just buy a teddy and play a game with her!! You can date her to go to the Ocean Park and play all day so you and she will hae fun!!!
Wish my suggtion can make the girl happy!!