Muffin is missing

Muffin has been gone for more than a month. She was born outside, daughter of Kairi,

granddaughter of Brindle,

and sister of Puffin and Nuffin.

Muffin began living in the outside shelter when her kittens, Mini and Maxi were born, to shelter them from the big tom cat.
She liked to go out every day but would return at night.
A couple of months ago she went away for two weeks, came back and stayed for a week, and then left and didn't return. I am guessing she is okay, as she is a good hunter, but I haven't seen her.