Thanks for the extra info. You can upload pictures if they are sized small enough using the green tree icon on the tool bar.
Whle these could be from mammary gland infection due to clogging after nursing was completed my worry is the spots you are seeing may be due to a bleeding disorder and the purple color is due to bleeding under the skin.
This sort of problem can be an inherited issue or might be due to a tick carried disease or another health issue. This site has 6 pages of info on the problem linked together
scroll down past ads on each page to see all the info.
Bleeding can also be due to ingestion of rodent bait.
While red spots on gums and abdoment are one sign another is bruise spots along the abdomen.
This may also be due to infection under the skin leading to abscess formation that may open and drain.
You can read about more causes of lumps and bumps here
I'd plan a vet visit for her.
If your dog might have gotten into anything toxic, appears dehydrated (see if a pinch of skin over the shoulder blade stays stuck in a tent form or flows back down normally when released), has a rectal temp over 103.5F (normal is 100.5-102.5 Fahrenheit or 38 - 39.2 Celsius ), has gums or tongue that look white, blue, gray or yellow tinted where they are normally pink, has a slow color refill if you press on a pink area of gum or tongue, is not breathing well, or is becoming lethargic and non responsive to you then you may want to get the dog in to see an emergency vet if one is available in your area.
This site may help you locate an emergency vet if you need one
Hope this helps you!