Isn't there something I vaguelly recall called "gutty girls" or similar, about a group of women working cleaning fish? And I found in about a 1940s copy of "Plays of the year" collection of short plays, one with an all-female cast of women in the aftermath of a war, all different ages and types. I can't lay my hands on either at present, so long since I've needed them, but try an internet search with the criterion "all female" and I'm sure loads will come up. Mind you, often you can change the sex of characters in existing plays, some girls mind, others don't, that their character "was male", you might end up getting a re-type!! I also have some recollection of a play about suffragettes. It's just as tough with all-male groups, too. Good luck.