I am sorry you didn't get a reply until now. That is days ago. Did you take her to the vet?
I would say heavy bleeding while in heat is NOT normal at all.
It could be a sign of an infection, possibly pyometra?
My own dog was about 12 when she got pyometra, and the morning of the day I ended up having to rush her to the vet, she also ate her breakfast.
I hope your dog is okay?