SF Story/Novel ID: Angels, Menses and Faces (oh my!)

We're not having much luck: Can you help us solve find this science fiction novel for a patron? Here's their description:

"I'm trying to figure out a book a read many years ago. I *think* it's by
Sherri Tepper, but I can't figure out what it is. Here's the story as I
remember it: Young women when they get their menses (see? So Sherri
Tepper)are sent to spend the night in, like, an open air hut or something? And
then frightening creatures, who are like ravening angels? Sort of? Come
and A) rape them and B) eat their faces. (Tepper. Pretty sure.) But their
supposed to be ancestors or something? Like, when people die they become
these things? And then the first child of most women (due to that whole
rape thing) are these creatures? And maybe everyone lives in a glass
bubble? Because I think there's a scene at the end when the
ancestor/angels are attacking or something? Anyway- any idea what that book is? Thanks so
much!"

Thanks!

 
David Wright
http://shelftalk.spl.org
        
                  "Que Scay-Je?"