Sorry, I came here to edit my comment and just saw Opus88's comments and I do agree that she does need to see a vet. :)
My edit was to say that if she is acting normal, that is a good sign and she might be able to wait till tomorrow to see the vet.
OY, sorry for all the babbling, it's late here and past my bedtime. :P Please do keep up updated on how kitty is doing. :)
Yep, if she is acting normal, then she will be fine and can wait till tomorrow. If you can keep an eye on her throughout the night though, that would be good as she MIGHT have more kittens, but also might have just had the one. :)
we aren't Vets on this site, its impossible to give medical advice.
all I can say is trust your own judgment, and monitor how your kitty is appearing, is she acting normal...eating/drinking/using litter box...or does she appear distressed and in pain? is she straining and trying to deliver more kittens? Is she bleeding?
You need to monitor all this and decide what needs to be done....
Whether tonight or first thing tomorrow this kitty DOES NEED to see a Vet and have a good check up...she may be carrying more dead kittens and not able to deliver them...
good luck and please keep us posted..♥