While Serenity and Joss could certainly take care of Thomas and Jamie's cats, Charlotte wanted to help out too. It made her feel like she was doing something to head over to the duplex and water all the plants and spend a few hours talking to the kitties. She felt so powerless after all her loved ones had gone through lately. Lena, Maddy, Jamie and Thomas had been attacked and tortured by demons and Charlotte didn't know how she could possibly begin to help with that. Feeding cats was mostly to make her feel better.
When the knock sounded, she pushed Thomas' cat off her lap and bounded over to it. She pulled it open and smiled kindly at Aiden on the other side of it. "Oooh, you have a box! Who is it for?"