Could you borrow a live trap and try to catch the mom? That way she can be taken in and gotten fixed and then there are no more problems with tiny babies being killed by machinery. It would also help with the pet overpopulation. Maybe your coworkers and you could swing a deal with one of your vets and then split on the cost. Or find a low cost s/n place.
Wellness is a pretty widely available food. If you have a Pet Valu or a half decent pet store you should be able to get it. If not try to find one with no by products, grains and corn. Cats need meat, not fillers like grain and corn.