Bachelorette Party near Philadelphia?

Hey all! Planning way ahead for my Bachelorette Party weekend sometime next summer (2021) because my bridesmaids are already inquiring!! Only requirement is that it is within reasonable driving distance of where we all live which is Philadelphia. We don't want to do AC since we've all been there, done that. We have three options currently: Dewey Beach, DE (my MaOH went here on a bachelorette party last summer and loved it), Ocean City, Maryland & Boston, MA. If anyone has any input on these, I would surely welcome them or any suggestions for other places we could go! For some more context: there will be approx. 7-12 girls, we're looking for good places to eat, some fun bars to go to, other fun activities to do, and somewhere we could rent an airbnb/house to stay at. I also want to make sure my younger sister can be included in some ways. She will only be 18 so not legal to drink, but doesn't mind hanging back at the house when we go out at night (she'll be bringing her BFF with her so won't be alone/bored!) I just want to make sure there will at least be some things she can be included in. Thanks a ton!