We seem to be having the opposite situation. We found 2 small kittens living under our porch. Keeping them was a problem with our landlord's wife so we fed them and tried to take care of them while trying to find a shelter or rescue that could take them. No such luck! Finally we decided to keep them. As we were getting ready to bring them inside, an adult cat showed up literally out of nowhere. Even though this older cat has very similar markings and color, we're not 100% sure it's their mother. Well, this older cat now won't let us get anywhere near the kittens. If we try, she'll put herself between us and them then hiss, bare her teeth and take the attack position. We're at a loss trying to figure this one out especially since the kittens were here alone for quite some time and are certainly old enough to be independent of their mother. Right now we're attempting to get a humane trap for all 3 of them so hopefully they can go to a better situation.