Sounds like things are going good. A little slow, but that's ok too. So cute how Kia immediately rolled over and showed her tummy when Little Boy hissed, and it's funny how that reaction caught Little Boy off guard. I'm sure the dogs he came across outside weren't quite as friendly as Kia is. And it sounds like Zam is getting used to him - and vice versa - if they were near each other with both purring.

Just takes a little time - and a lot of patience , which you seem to have, so I think Little Boy will be just fine, and fit in with the others in time.