When my son was little we had his whole class over for his b-day. It cost almost nothing because we did "stations". Gak station. Homemade playdough station. Bubble station and I would bet, cuz he's that kind of kid, a lego station. Oh, a writing this makes me think we did a spin art station with a salad spinner. Everyone had a great time and parents stayed to help because who wants to be the only one with twenty kids running around? With five year olds you could even have a chicken petting station. Money doesn't count. Fun does. Parties are great opportunities to start learning manners and good hosting skills. I never let friends bring presents, but they could bring things to do. Presents were for the family get together. Your daughter might have some very good ideas about what would be fun activities for her friends and that starts her thinking about other people. As to where, well, parks are fee and in four months it will be nice outside. Minimal clean up!