A.G.
Start with a couple of pizzas and afterwards they can get into their pajamas and watch a couple of movies. Once the first movie is over, they start telling stories and giggling, so they don't even watch the second one!
Karaoke is a lot of fun too, and if they do a little dress up with boas, hats, fake jewelry, some makeup, they'll enjoy that too.
You can have a manicure session where they do each others nails. Prepare the station with nail polish remover, cotton balls. Give each girl a small bag. with a clipper, nail files, cuticle oil, clear nail polish, etc. to take home with them. Enjoy it all. Happy Birthday to the B-girl.