Obviously they start nesting and doing all that common stuff either way pregnant or a false-pregnancy. You can't tell by looking at how they act ... at least I couldn't do it.
I used to raise champion dogs, Basset Hounds, but NO PUPPY MILL. Take her to the vet and have him check her. You need to know so she can get on vitamins and you can do the right things for her and the babies. She needs help just like a human mama.
I used to give pups their shots myself, do things for the mamas (Maebelline and Eli Mae ... Eli was Mabel's first pup) and all that but I was set up for it. If that dog is really your friend get her to the vet and get her checked out. She can't do it herself, she needs your help. God bless.
I am not a dr. My statements are based on years of experience and related education. Consult with the professional of your choice regarding matters of concern.