Hello all. Any suggestions, tips, insights are welcome. I have an almost 6 month old female kitty that we have gotten from someone in the area that was giving away her cat's litter. We have not brought her to the vet yet. On a very, very short notice we got a possibly 8-12 weeks female kitten 3 days ago. She was found on a coworker's front porch. Because it was so sudden we did not plan for a second kitty at all and did not do the separation process to begin with. She was bathed before we got her but she has now been bathed with the same shampoo as the resident cat's. Now the resident cat has gotten to the point of running up to the new kitty and hissing at it. Sometimes also whacking her (no injuries so far). Now the new kitty has started to hiss and fight back. The resident kitty tends to chase the new one and also hiss at it while its in the litter box. We would really LOVE to keep the new kitty as she complements the resident kitty but we are unsure if this is recoverable. Does anyone have any stories or tips? How long should we give this until we should call it quits? Thanks in advance!