Rey (a Kenobi, for arguments' sake) admires Leia and wants to be closer to her, but decides pursuing her romantically should probably wait until after they can all process Han's death. A friendly bonding session goes awry at the base and they have an intimate encounter despite grief and personal resolutions to keep it platonic. Guiltily they struggle not to fall for each other - and yet their feelings deepen- perhaps while communicating along force bonds after Rey goes to train with Luke?
Rey/Leia, they aren't related but it's still complicated