Welcome to Boise,
There is: These are good places for her age.
Build a Bear workshop at the mall that does birthday parties from $10-20 per child, kinda pricey.
Also Micheals craft store on Franklin and Maple grove do great craft parties for all ages, very reasonable on prices and they have a great room for this, you bring the cake and they supply all the fun and the mess stays there..great fun!
Monkey dooz is a salon that caters to little girls and does birthday parties with a spa theme, never been, but here it is fun for girls.
Artist for a day, does ceramic parties for kids of all ages. fun time, and the kids get a great project to take home.
Magic Tumble bus is a bus that comes and has lots of fun tumble activities inside the bus for those young 3 year olds, kinda different and neat, the kids think it is neat that the bus comes to them.
And always: McDonalds, Chucky cheese, pojos, Discovery center, Carls Jr., Burger king, Idaho ice world, roaring springs, Boondocks for put put and go-carts, Lots of local clowns and magic men. lots of inflatables. YMCA, bowling.
Have fun, and enjoy!