I have a nephew age 6 and an niece that will be 5 in October and I can tell you, kids don't care how much you spend, they just want something to open. The best gift I got for my nephew was a Thomas the Train magnetic board. It was just a flimsy magnetized board with train-shaped magnetics that he could move around. I spend $3 on it and he loved it. Played with it for hours, making little train noises. The other toys that I've spent more money all just got set aside.
So I agree with everyone else, anything in the pink aisle. I just wouldn't worry about spending a lot of money on it. Wait until she is older and will appreciate it more. The crafts aisle has also been a good source of ideas for me (especially because I don't necessarily need to know what is hip in terms of cartoon characters to pick out a fun craft). Play Doh always goes over well and comes in infinite varieties. Children's books are another good idea.
Try to avoid toys with lots of small parts because those get lost in a day. Also, if you like the parents, try to avoid toys that make lots of noise. Or if you want to get revenge on them for not giving you any suggestions, you could go the opposite route.
