Nebula is moments from death when she's pulled through the airlock, but the "You should've let me die" that she manages to rasp out between her wheezing is clear.

Gamora feels her jaw begin to clench, because even if she'll never provide the satisfaction of showing it, she knows her sister is right; it'd been a stupid decision, and sooner rather than later, it's going to cost her. She turns from view, and says, voice even, "Next time, I will."