Well, the cats are finally getting along with each other. Merlo, of course, was never the problem, being the new addition and a kitten at that. Keena, on the other hand, needed to adapt to having another cat in the house.
When Keena first met Merlo, she hissed and spitted and growled, and she and I had a nice argument which ended up with her under the bed in the spare room with a semi-permanent growl, and me with a huge migraine. She kept up the hissing and spitting and growling for most of the rest of that week. We couldn't actually bring Merlo anywhere near Keena. Of course this was probably exacerbated by the fact that for the first 3 nights we let Merlo sleep in our room with us.
That ended soon enough though, since she'd started keeping us awake by bouncing all over us and nibbling any part of our faces that she could find. However, with the lingering smell of Merlo in the room, Keena avoided "her special spot" for the rest of the week. During this time, we continued trying to introduce them to each other, to no avail.
As week 2 started, we noticed that Keena was getting less and less agitated about Merlo. After lots of love and sweet talk and treats, by the end of week 2 she would tolerate the little kitten being in the same room as her, even if it was just by ignoring Merlo completely. She'd also started sleeping on the bed with us again.
As time went by, Keena started getting more and more accustomed to having Merlo around, as her position as Queen of the House didn't seem to be usurped by the small intruder. In fact, by the time it got to the end of week 3, Keena was even tentatively playing with Merlo every now and then (mostly when she thought that neither mom nor dad were looking).
While I think Keena is still cautious and somewhat distrustful of Merlo, she seems to be happy to play with her (I think she's happy to have a playmate). Keena will often chase Merlo around the house and then outside into the garden, and then she comes rushing back inside, with Merlo in hot pursuit. Yesterday I saw them play-fighting, legs kicking and paws swiping at each other, and at one point they were "buried" in each other. It's quite funny to see the two of them playing, Hannah and I have had a good laugh on a number of occasions.
I've been keeping a watch on Keena to see that she doesn't use her claws, but since Merlo has yet to be injured, it looks like Keena is indeed being careful and doesn't want to hurt the little kitten.
The one thing I have been a little surprised about is that Keena hasn't mothered Merlo. I thought that she would do that once she'd warmed up to the kitten, but as yet she hasn't. Well, I suppose it could still happen. I don't think Keena is "friends" with Merlo yet, judging by the expressions on her face when she sees and plays with her, but that doesn't mean she won't get there. At this stage I'm keeping to my "let's wait and see" approach.