When I came home this afternoon, this is what I found.
Clarabelle and Hermione haven't always gotten along. When Clarabelle first arrived, Hermione was very upset with me, hissing and hiding all day. I felt terrible.
Clarabelle was so sick, she didn't care, at first. By the time Hermione came around, Clarabelle was feeling better.
They will occasionally groom each other; Clarabelle will more often groom Hermione than the other way around.
I have no idea whose idea this was, or who arrived first. My guess would be Hermione curled up with Clarabelle, but I will never know for sure.
Either way, I think it's safe to say that these sisters have bonded.
And that makes me feel all warm inside!