How old will she be? Would she like a character meal with the Princesses in Ariel's Grotto? Make sure to get her a birthday sticker at City Hall. All the CMs notice the birthday stickers.
We are taking my son who will be turning 4 on September 26th We are pretty sure that anything we do down there will be great for him but like you we are planning on doing character meals. We will be going to the Lilo and Stitch breakfast and likely Goofy's one night for dinner. We went to Ariel's Grotto last year before it changed over to princesses and the deck with the view towards the Sun Wheel at sunset was Amazing!!! I love that restaurant, you guys will have a blast.
Other things we are planning on doing is the Pat E Cake birthday party thing at the plaza and beyond that we are just going to take it easy and enjoy disneyland. We are going to get him a happy birthday pin instead of the sticker from City Hall because he just takes stickers off; they offend him somehow lol. Basically that day we will follow his lead and see what he wants to do; we'll probably spend the day on the tea cups but that's fine. For gifts I'm going to make him an autograph book/scrap book that will have his picture with the characters on one side and the autographs on the other. He really likes photo albums and loves looking at our old disney pics so for him this will be a perfect gift that he will love for years. He'll have something to open that day too; but the big gift is really disneyland anyways
I keep adding this thread to birthday questions It's only because I saved it for next year when my two DDs will be celebrating their birthdays. Here you go: http://www.disboards.com/showthread.php?t=1089300
I'm not sure if she's old enough for Club Libby Lu, but little girls seem to really like it there. Aside from that be sure to get a birthday sticker for her to wear (available in City Hall on Main Street).