Cat swallowed dentle floss!

What should I do? Should I wait to the morning to take to vet or take her now??

First I'd like to say welcome to TCS!. 

2 of my cats Reilly and Sydney love to eat things like that (Sydney in particular ).  I think you should give your vet a call.  They may want to see your kitty now or give you instructions as to warning signs to watch for in the case of a blockage.  Either way with something like dental floss it would be a good idea for the vet to monitor the progression of the floss in case it gets tangled up on the way out. 

Please keep us posted!.
 

I'd call the vet to ask. But it would certainly be easier to remove from her stomach than have it removed if it gets wrapped around her intestines. How much did she swallow, do you know? Is it possible she chewed it at all so it's not one big long string? My cat ate about a foot of a wand toy string twice in her life. Both times she must have chewed it up (though it wasn't coated with that kind of waxy/plasticy stuff that dental floss is), because I checked poop in the box for four days after she ate it, and it never turned up, and she never had a problem from it that required a vet visit. But dental floss is a bit of a different animal, so to speak. A fiber-based string they may be able to digest and excrete. But I don't think dental floss can be digested.

Vibes for your baby.

If your cat  tries to pass string in the stool and you see some sticking out, do not pull on it. I hope your cat will be okay.