More representation for female beards! I love it.
Personally, I interpreted "a rock and a hard place" figuratively, being stuck in a difficult situation, between two impossible choices. You could think of it as her being a dwarf (rock, and the character's struggle with her identity) in a "hard place" living and working among humans, and feeling out of place away from her community - a common experience in our own world, for people who decide to leave their culture and families behind in order to provide for them. And the prejudice they face, on top of their feelings of isolation, is a concept certainly worth exploring. I suppose you could emphasize that struggle more, if you wanted, but I think you did an excellent job.
And as others have said, the twist at the end was excellent, and you did a great job with foreshadowing, talking about the "human writing," even though the reader wouldn't realize it till the end.
A great read!