Books.
Stuff without batteries.
Craft-y cut it up and glue it together kits.
If she's attuned to the baby, maybe a baby doll of her own. I'm not sterotyping here, I'm trying to read your vibe. I saw a commercial this weekend of a "Mommy make me better" baby or something like that. Brings out the inner nurturer. The dolly has red leds behind her translucent cheeks. They glow when she has a "fever" and dim when the "medicine" is administered. The same for the heart shaped boo-boo on her wrist when covered with a band aid.
A musical instrument.
A special trip somewhere--the zoo, the museum, the science center.
A bike. I remember fondly my first two wheeled bike. My world expanded dramatically when I had my own "wheels".
A ball to play catch with. A glove. Not a baseball whiz yet? How about one of those kits that have hook covered paddles for the hands and a fuzzy ball. Velcro catch. Veeerrrrry easy to succeed. Or a throw toy called a foxtail--a ball with a long (three feet) fabric tail. If you miss late on the ball, maybe you'll trap the tail.
A kite.
Clothes. I love the sons and the daughter (and nephews and nieces) equally, but you have to admit, the girls are a lot more fun to decorate.
Jewelry, maybe a special pendant or earrings? Can she get pierced ears yet, Mom?
I could go on and on. I love kids.