Advice needed: introducing kitten to resident cat

Introducing a new kitten to a resident cat can be a tricky process, but with patience and proper management, it is possible to help them get along. Here are a few tips that might help:

Keep them separated for a while longer: It's important to give your resident cat enough time to adjust to the presence of the new kitten. You can try to separate them for a few more days or even a week to help them get used to each other's smells and sounds.

Use scent swapping: Try swapping their bedding or rubbing a towel on one cat and then placing it near the other. This can help them get used to each other's scents and may reduce anxiety.

Supervise their interactions: When you do start introducing them, make sure you supervise their interactions closely. Try to create a positive environment by playing with them together or feeding them treats in the same room.

Provide safe spaces: Make sure each cat has a safe space to retreat to when they need a break. This can be a separate room or even just a cardboard box with a hole cut in it.

Slowly increase their time together: Gradually increase the amount of time they spend together, starting with short supervised periods and gradually increasing the duration.

Remember that it may take some time for them to get used to each other, and it's important to be patient and give them the space and time they need to adjust. Good luck!

Just don’t force it, leave the doors open so your older cat can retreat if it wants to but can observe the kitten. It won’t take long for them to accept each other. We had to do it with my cat when we got a puppy. They sleep in the bed together now

Bring a borrowed puppy in at first to show the cat. Then take the puppy back to the owner and bring in the kitten. The cat will be grateful it’s a kitten and not a puppy.

They will get along before to long

Takes time. You sound like you are doing things right. Fo give thenolder cat time away from the kitten. They will, in time, get to like one another. Kittens havevtons of energy. Older cat knows this. She is older, tired, wiser. Give them time. And treats
And affection.

Sorry to say it, but I just wouldn't introduce a young rescue kitten to any cat that was used to living alone in its home territory. It's just not fair to the older one.
I'd find the kitten the right home (no older cats) before it grows out of it's kittenhood.

You should apologize to your old cat.