Hello,
At this point, either that puppy needs to be manually removed or both the puppy and mother are at serious risk. If the puppy is coming out feet first or tail first, it can sometimes be manipulated to head first and removed. If it's head is stuck, then it probably won't come out vaginally and c-section is needed. I would absolutely get to an emergency vet tonight. I'm worried that if this goes on too long (which is has already) the puppy will tear through the uterus and then the mom may die of a septic peritonitis. C-sections are usually around 1500 at my emergency clinic, but it does vary. I'm sure they can work with your about funds (care credit is an option), but she needs to be seen now.
Hope this helps, let me know how it goes.
Dog Veterinarian
DVM, Emergency Veterinarian; BS (Physiology) Michigan State Univ