Mirabel is the one person in her family with no magic powers and feel lesser for it. She sees that their magic is in danger and tries to find out why. She asks around until she finds her estranged uncle Bruno and he tells him how to fix this. She finds out it's because of her families issues, and they resolve to fix it.
And for the novel I'm writing, it would be:
Steve is a human insect hybrid who looks human, and is terrified of being found out. He reconnects with a childhood crush Will, but Will starts turning into a hybrid himself. They seek out a cure, but they fail to get it and Will ends up looking unrecognizable as a person. They stay together in spite of this, and flee the country together.