Cant find stray cats kittens!

Question
Hi, a few days ago a stray cat that was very small and skinny and obviously had had kittens (her teats were very large and swollen) came up to my girlfriend at work and wolfed down the dog food she happened to have in the car. The next day the girls at her office called to say the cat was IN THE OFFICE (it must have snuck in behind one of the other girls) and we came and got her.  The problem is, where are the kittens?  The cat is VERY loving and obviously not feral, but we have no idea where the kittens are or if they are still alive.  She does not seem to be looking for them; we walked around with her outside my girlfriend's office but she was more interested in following us than finding her kittens.  We took her home, and she seems very relaxed, no signs that she is stressed and missing her babies. We want to keep her but we hate the idea that her kittens are out there alone.  However it doesn't seem like she has any maternal instinct, so perhaps they did not make it?  She's got some bite marks on her and I thought perhaps she had been attacked and they had been killed; or she was young and did not know how to care for them and they died, or died for other reasons.  Any insight would be very apppreciated.

Answer
She may be very yound and ofen they aren't great mothers at that stage. Finding her kittens would be best done by listening for their crying as they will be crying for food unless they have passed already or are too weakened to do so. Check behind and under things all around the area. they ususally don't have their kittens in open, exposed places. If she has hidden them and there is no clue, it may be too late. It also may have been a while already and they are already gone but she may still be swollen because of an illness like mastitis. She should be taken to a vet for this and also a full check up for parasites and disease. This is imperative and urgent. For example, even if you feed her well she may not do well if parasites are consuming her or she is carrying an illness. She must get to a vet.