Yellow looking stuff coming from vent sounds like an egg broke and she probably has an infection from that, but that is just a guess. If I were you I would do a cloacal exam and remove any of the egg and/or shell that's still in there and I'd start her on Baytril, which you would have to buy from a vet or order online unless you have other drugs like Clavamox, Cipro or Augmentin, you could use those, too.