Mizaki, thank you so much for the answers.
It's too bad that any interaction doesn't increase their Happiness.
I have more time to interact with the kittens, but I'm sure she will make time to ensure it stays happy.
As for the basket, I thought maybe it was like the Starter food...only for your cat and once they mature in 7 days, then they both will enjoy it. I guess we'll see soon.
Again, thanks for the quick response.