A second vote here for the off-broadway revue: A...My Name is Alice.  There is some amount of language involved (which could be cut and/or revised for a high school crowd), but it's a revue format, 5 actresses (or more if you want, easy set requirements, can be done well with a piano/drums/bass combo and very, very funny at times and moving at others.

I've had enormous success with it over the years - placed in the top 10 at the American Association of Community Theater festival some years ago.

Good luck.

If you want something artsy you could use:

For Coloured Girls Who Consider Suicide When the Rainbow Is Enuf.

Others:

The Women is great. You could do a version of Edgar Lee Masters Spoon River Anthology with just the womens sections and you could create it yourself.  Great for monologue/character devolopment

go to samuel french and dramatist website and take a look as you can brouse on line.