My heart goes out to you and to Butterscotch.
I am so sorry for your loss.
My thoughts and prayers are with you and I have said a special prayer for the little lost calico baby. I am having the same problem here in my little "feral country". Two kittens from one of my ferals have disappeared..one little black one and one little gray one. It is heart breaking but that is life as a feral I guess. We save the ones we can and as for the rest we must just trust that they are in a better place.(which isn't always easy to do).
If I may I will refer you to a good pet grief site.
www.In-Memory-Of-Pets.com
Check out the Candle Light Rose Ceremony. It is beautiful.