Kitty Sibling?

Not our "cow kitty" but a close facsimile

About two weeks ago we noticed a new kitty wandering around our garden. We've named her the "cow kitty" since she is black and white. But poor little thing is thin and dirty (the white is more a dingy grey). She seems to enjoy relaxing under or near the bird feeder. I've not seen her chase a bird (and I haven't found any "remnants" of a kill). I think she gravitates to that part of our yard because it is directly in front of our kitchen--the hub of activity in our home.

Pumpkin has certainly noticed her. But his reaction to her is significatly different from his "opinion" about other cat visitors to our backyard. He doesn't hiss, moan, or yell. He hops onto the window sill, tilts his head to and fro, and occasionally utters a low warble.

I'm beginning to wonder if they are, perhaps, siblings.

They are about the same size, have the same head shape, and the same l-o-n-g tail. Only one characteristic of "cow-kitty" is different.

Dear kitty is decidedly cross-eyed.