Female Pit Will Not Gain Weight?

I have a 3 year old red nose Pit Bull. She had puppies for the first time by our blue nose brindle, but now that the puppies are 8 weeks old she still can't seem to gain any weight. We feed her almost 5 times a day. I give her soft food, as well, mixed into her dry food. We had tried puppy food even cuz I have heard that helps with mother dogs after having pups, but it seems like despite everything we do nothing is working.

I feel extremely embarrassed to take her on walks, people look at me like I'm a bad mom, like she's abused, but I assure you she is not abused what so ever! Please if anyone can give me some advice that would be great. Thank you.

By L.A.M