S.C.
You would NOT be a bad mom. Your daughter will be fine if you pull her out of pre-k. You can teach her things at home if that is the main reason she is in pre-k. You can get flashcards, dry erase books that teach alphabet, numbers and shapes,colors at the dollar store. Don't forget to go to the library too. Many have story time and its great to get her new reading/learning material at no cost. You can also get her "socialized" this way if that's what your looking for. Our library is a smaller one and the same families usually come every week or every other week to the story time. I think even the Barnes and Nobles has story time so you could get some you time too. I would recommend taking her to a zoo if you have one near you, mommy and me classes, playgroups, MOPS (mothers of preschoolers) if there is one near you and all of you could go. There are so many alternatives to traditional pre-k and she can still learn so much. There are good websites too that offer free activities for toddlers to do at home, you just gotta dig a little (i love the national geographic junior site and the PBS site)
If your income is lower you might look into WIC or something like that to help with your food costs. HTH