This book has a planet with all females. The planet is linked to another world.
The protagonist falls to that planet and is found by a brother and sister. I think the sister could understand her or she could understand the sister. I remember them locking her up up in a cage with other magical creatures like a tree which she can talk to.
I also think the high priest of the other planet has some plot to keep in power. The brother and sister free her and they go on a journey. It's vague but for some reason the story keeps popping up in my head and driving me crazy. Can anyone help?