Probiotics may take time to work. Have you tried plain fat free yogurt? Pumpkin can go both ways: either firm them up or loosen them so if you haven't seen an improvement, I would say stop. You could also try not feeding kitty for 12-24 hours (only give water) and then give her rice with boiled chicken. Also I've used cat anti-diarrhea medicine from Petco which helped some. Give it time. Once the antibiotics are out of her system she should get better.