It looks like you have gotten some good advice about your options, the risk involved, etc.
If you have chosen to let your girl have puppies just get prepared.
Have $thousands available for vet care if needed.
Be ready to take time off.
Ask your vet many questions.
Finding a mentor would be good, but ultimately the first priority is a good vet. I know if my furgirl was having puppies I personally would want my vet to be near because they can examine mom, give drugs, do emergency surgery, etc. So if you try and can't find a mentor just talk to your vet about it.
Not sure why there is a big push for ultrasound. Unless your vet believes it is necessary you may not need to. A lot of people choose to wait and xray. If you are not sure that she is pregnant (could be pretty hard to tell the difference between that and fakse pregnancy) then treat heras if she is.
The diet needs to be changed.
Talk to her vet,
