Jyn doesn't want to be thanked for that, so she takes another swig of her beer, more controlled than the last. Just a sip.

"My parents are dead, Saw is dead." Rey is half her, all that's left of her parents and her grandparents and her great-grandparents. She's not an Erso or a Gerrera, but she is made from that. Jyn couldn't handle the idea of losing that, even if she didn't really feel anything toward Rey until after she was born.

"I couldn't lose any more family."