I've recently just found this article on complications after spaying and thought you maybe interested in reading.
I sure hope your little girl is better now...if not please return to your Vet asap....♥
http://www.pet-informed-veterinary-advice-online.com/spaying-cats.html#complications-spay
you need to find another Vet, something is very wrong indeed......darn these professionals, what do you mean they couldn't find anything wrong!!! this isn't normal NO. she has either aspirated or is having a very bad long term reaction to the anesthesia. she will be dehydrated and soon have more severe problems....please demand better care from someone before you loose this poor little girl.
this is very unprofessional, my clinic ALWAYS phones a few days after any surgery to see if everything is alright...if something isn't they WANT to see the patient again immediately and at NO cost.................demand some answers and some care for her sake.
please keep us updated....♥