Someone You Can Build a Nest In by John Wiswell

Shesheshen is a shapeshifter, who happily resides as an amorphous lump at the bottom of a ruined manor. When her rest is interrupted by hunters intent on murdering her, she constructs a body using a metal chain for a backbone, borrowed bones for limbs, and a bear trap as an extra mouth. However, the hunters chase Shesheshen out of her home and off a cliff. Badly hurt, she's found and nursed back to health by Homily, a warmhearted human, who has mistaken Shesheshen as a fellow human. Homily is kind and nurturing and would make an excellent coparent: an ideal place to lay Shesheshen's eggs so their young could devour Homily from the inside out. But as they grow close, she realizes humans don't think about love that way. Shesheshen hates keeping her identity secret from Homily, but just as she's about to confess, Homily reveals why she's in the area: she's hunting a shapeshifting monster that supposedly cursed her family. Shesheshen didn't curse anyone, but to give herself and Homily a chance at happiness, she has to figure out why Homily's twisted family thinks she did. As the hunt for the monster becomes increasingly deadly, Shesheshen must unearth the truth quickly, or soon both of their lives will be at risk. And the bigger challenge remains: surviving her toxic in-laws long enough to learn to build a life with, rather than in, the love of her life.