American Girl used to make very expensive birthday party kits. My daughter had an AG party two years ago when she turned 7---but only because I got the $200 kit for around $50 - they were on clearance at the time. I haven't seen any kits since. Hers was a luau/tropical themed one. They had paper lanterns, flower lei kits for the girls and dolls, cups/plates/napkins/silverware for the girls and dolls, along with a treasure hunt game. I imagine you could recreate something similar with whatever theme you choose and try to incorporate a smaller version of a craft for kids to give their dolls. Maybe make some "mini" cupcakes for girls to serve their dolls, etc.