Introducing cat and new kitten: advice needed

[Davespecifico]

We have a 1.5 year old BSH girl. We have just brought home a little 14 week old colourpoint girl. We have read lots and my dd has watched numerous videos on introducing cats.
We have therefore decided to take introductions slowly and have a Feliway plug in and a spray from another brand. The kitten has her own large, warm bright room at the top of the house. We’ve kept them apart overnight and for the first morning. This afternoon we let the cat explore the kitten room alone. Then we let them smell each other’s scent through a closed door and then through a slightly ajar door. The cat hissed, several times, tried to jump at the kitten to attack her and did a kind of threatening miaow. We then took the cat out and settled them both.
Any tips on what to do next. We’ve looked at a temporary barrier. Is the hissing typical. Thanks for reading.

Bump

Hi. Sounds like you're doing everything right. When I introduced my kitten to my older boys one of them accepted him within a week or so. The other took months of hissing and sulking - he was very upset by it. So I think each cat is different.
Once you get to the point where you can safely have them in the same room try feeding them together.

Thanks Georgie.

Good look with it. I think patience is the key. And don't rush it

You can also put kitten in a carrier on a slightly raised surface (like a chair or desk) and let the older cat approach if she wants to - kitten will be safe in the carrier and older cat can safely get closer. Don't force any interactions, go at her pace.

I found the cat in with the kitten just now. She must have pushed against the door a lot to open it. I don’t know how long she’d been there. The kitten was at the top of her tree.
Once the cat saw me she did a long miaow (angry one) and hissed at the kitten several times. I then shooed her out and gave her a treat. The kitten seemed fine after.
I’m just wondering, is it possible that my arrival prompted the hissing, and that if I hadn’t she might have just continued to investigate the kitten? Did I make the situation more tense by being there?
Thanks

I've just read my post. Look instead of luck. I hate myself!
That sounds like progress! They were in the same room!

Get Feliway Friends plug in. It mimics the hormones released by mama cats when they give birth; it eases anxiousness and promotes bonding between the cats. Our breeder told us that the older cat would recognise the kitten as a baby and no threat so just to let them meet without easing them in. It worked really well. There was was some wrestling but kitten would make submissive movements and the cat seemed understand it wasn't a threat. We did follow them about and intervene when he wouldn't let the kitten go. They were best friends in a few days.

We also gave the older cat lots of cuddles and attention so he wouldn't be jealous.

Thanks both. Kitten has been here in her own room now since Sunday. When should I let them be together (with us there)? I’m back t9 work on Tuesday. I’m nervous that one, the kitten will be alone for the day and 2, what if the cat breaks in?