VANITIES by Jack Heifner
Swoosie Kurtz was in it originally. All girls/women.
"Talking with…" by Jane Martin
Also all women. A series of great, often very funny monologues.
Also, I went to an all girls school, and we actually did a lot of shows where we re-cast roles as female. Have you thought of doing that? There's a really interesting play, "The Visit," (by Friedrich Dürrenmatt) where you can do that with most of the suporting cast. We did, at least.
Hope that helps a little!