I would recommend getting some digital "stamps" online. Why? No messy ink. You can print a
bunch of them from your computer. Get a large container of Rose Art pencils so the girls can color. Get a few spools of skinny ribbon and some stickers at Michael's or Archivers and you are all set.
I used these digi-stamps for my granddaughter's birthday....
Frillie Millies from Pink Petticoat stamps are soooo cute. Prices are in British pounds, but they are very inexpensive.
Wendalyn's blog has a list of many other digi-stamp sites along the right side-bar. Just scroll down a bit and start clicking.