My Lilith did the same thing after about 4 days....her problem was she wouldn't stop cleaning it and she hated the stitches. Her incision sounds very the same why you decribed Kimi's. I watched it closely for a couple of days as hers was leaking a little blood too but decided it was best to take her back to her vet. They said it was the best decision and restitched the incision. They told me that even though there was a layer of skin already sealed within the incision that it was quite easy for it to get infected with her using the litter box. So my suggestion would be take her to get it restitched. I wouldn't want the little girly to get infected if it was preventable.