Monica, you need to work with her regarding location AND wardrobe. What does she have to wear OR is she going shopping? What look does SHE want. Pin up covers SOOOO much. I would suggest getting a pinup book from the book store and then looking at the ones you can recreate. Let her pick the ones that she likes and either has clothing or is willing to buy to get the photos.
You said you weren't sure that outdoors would work??? why not???
Girl on diving board, think Betty Grable in her iconic shot in 1944, with a tennis racket, rollerskating, with a camper, a canoe,having a pic-nick, on a swing in a tree, getting out of a car, wind blowing up her dress, and that is just a few ideas that you could do outside.
http://www.flickr.com/photos/autumns...on/4137161004/ http://www.flickr.com/photos/autumns...7622411170510/ http://freespace.virgin.net/b.mercer/Pinup1.html