Here are some tips for introducing a new kitten to your cat and helping them to bond.
Do the same thing with a towel that has your cat's scent on it and place it in the kitten's area. This will help them to get used to each other's scents.
Give each cat their own food, water, and litter box. This will help to prevent any resource guarding behavior.
Start by introducing the cats to each other through a barrier, such as a door or a baby gate.
When you first let the cats meet face-to-face, be sure to supervise their interactions closely. If you see any signs of aggression, separate them immediately.
Whenever the cats interact nicely, give them treats or praise. This will help them to associate each other with positive experiences.
It may take some time for your cat to accept the new kitten. Be patient and consistent with your introductions, and eventually they should learn to get along.