Whew! Hopefully it was just a hairball she was puking up! One of the only cautions I know about giving sub-q fluids, is if your kitty has heart issues. It just taxes the heart to have to absorb all those fluids. But if no heart problems, then 100ml shouldn't be an issue for most cats. Usually if the cat is really dehydrated, they won't eat much. So within hours of getting fluids, they get their appetite back since they're starting to feel better. Hopefully that's what happened with your kitty.
As for the falling over thing though.. that's not normal. :-| I'd really keep an eye on that. Do you think it was from the (cold) fluids feeling really weird to her?? Until they get used to the fluids, I imagine it feels REALLY weird to them. I give fluids to foster kittens when they're sick, and they act like it feels REALLY weird! Looking back, trying to flip over from the feeling. (They don't even react to the needle stick, but instead when I start pushing the fluids in!) If she was actually unsteady on her feet though.. that's probably from something else. If her BG wasn't low, then I'd definitely bring that up with your vet & see what they say. They might want to do some tests for some other things that may cause that..?