You absolutely made the right decision. Taking her home would have been for you and not Kiba. She looks like she wasn't feeling well. It's hard to imagine, but kitties have no sense of time. She wouldn't know it was her last night home. They live in the present. That's what makes them such wonderful companions. They don't think about death or the future. You were her meowmie and you knew in your heart what was best for her. She'd thank you for releasing her from pain.
I'm so very sorry for your lose. It's never long enough that they are part of our lives. You'll see her again one day. Take comfort in that. Hugs & LES from me and Calvin.