I think it depends, how is your bunny? Is she feeling pain ie trying to get to the claw? Is there blood? Is there anyway you can safely snip the claw off (not if it's into the quick) cornflour I believe has been used to help stop bleeding but personally if it's torn off at the root or into the quick of the claw I'd get it seen to the vets, she could be in serious pain & not eat in the night as a result, I think the fact you're asking means you'd be better to be safe than sorry & go tonight. Good luck.