[souffle]

It does sound like she has an abscess which has burst. Not all bacteria will respond to Baytril so it may be worth trying a different one such as Septrin. Raising pups is hard on them and she does sound to have had mastitis which is very painful for them. She could now have the infection in her bloodstream due to her condition and the outlook may not be the best in this situation. Keep up with the intense nursing and I would say she needs seen again. Has the lump filled up again? It needs kept open and draining to allow the pus to clear then she will heal up hopefully. You need to try and get her eating and if she is this ill I would try anything to get her eating - babyfood, porridge, yogurt, egg, soup may be taken.
I hope she rallies round for you