Oh yes, I noticed the notch. Was it from a fight or was it a notch put there by a feral cat rescue group? Since she was pregnant, I tend to think it was a natural notch, as I think the notches the groups put there are to indicate the animal was spayed or neutered.
I suspect she got it in a fight. Our shelter cuts the tip off one ear for TNR ferals, and besides, Patch was still intact (not to mention pregnant!) when she decided to live in the house with us.