What about a Photo frame? Or a picture book she can browse with her parents reading it aloud to her?
A CD with nursery rhymes would also be a good option, in my opinion.
You may also, however, start saving a bank account for her. That would also be another great option,i think.
She 's way too young to actively use it right now ,of course, but it will turn great when she Will be older.
Good luck...and happy birthday to your niece!