Hi there. Did anyone have an experience of observing a stray cat after giving birth? How long does a mother cat stay with newborn kittens before she leaves her nest for the first time?
Have you been feeding her regularly? If she knows to come to you for food she will probably show up in a day or two. Nursing mothers need plenty of nutrition. If you can give her some good canned food and some KMR it will help.
Outdoor cats and kittens don't live very long. It's not uncommon for cats to lose their whole litter, particularly if the mother is young and inexperienced. Is there any way you could bring them indoors? I understand that you don't know where the kittens are now, but if you feed the mother every day the kittens usually start following her when they're about 8 weeks old. That would be the best time to trap them and bring them in.