Promising introduction??

[TingaTinga]

We've had the new kitten since friday and have kept her in the spare bedroom and let the other cats sniff under the door. This morning we put her in the carrier and let the other cats sniff her. Resident cats didnt hiss and were just walking cautiously round the crate sniffing. The kitten hissed a bit but nothing major.
We did it again later and resisdent cats were indifferent and had a quick sniff then walked away.
The kitten is leaping around the spare room like a loon as shes used to having her brother to play with and now has no kitten play mate so has lots of energy.
So we let her loose in the living room with just 1 of our other cats (who is only 7 months herself) and she allowed the kitten to get very close to her with no hissing. We had fishing rods and they played just fine.They did hiss one time but think they made each other jump. Pics show how close they were with no reaction from older cat. Is this a promising start??

 

[ArtNJ]

A kitten and 7 month old are literally going to become friends almost every time, so I don't know if "promising start" is the correct term per se, but word quibble aside yes, absolutely, that relationship is going to be fine! If your other resident cat(s) are older, then yes, more outcomes are possible and you could definitely say its going well so far!

 

[TingaTinga]

Thats good to know! The other cat is young too. 9 months so hopfully he'll be fine too. The kitten and other cat are both females

 

[ArtNJ]

Yep, friendship is pretty close to a sure thing. If the kitten seems comfortable with you and the room she is set up in, you can just let them work it out from here. Might be some hissing for a few days, but the only real issue your likely to face is what I'll call "size difference stress". In other words, the play will look so rough that its likely to scare you. Its unlikely to be anything you need to worry about, but you can certainly come back and ask more questions when you get there.