Hi there, my name is XXXXX XXXXX I am a registered veterinarian and I would like to try to help you.
Does your puppy live alone, does she play with other dogs? Are the little lesions raised and hard, do they have fur covering them? Sorry to ask so many questions, it just helps me to give you the best possible answer.
Ok well scabs from playing are definatley very common in puppies but yellow lumps can indicate a bit of a skin rash.
Skin rashes at this age can be caused any a whole range of things from a change in cleaning products in your home to the start of an allergy to food or pollens.
If the little scabs seem to dry up and disappear and they are not itching or bothering her, I would imagine they are most likely from playing or are nothing to worry about.
However if they are itchy or 'pop' with a sticky yellow discharge then these are called pustules. Hard versions that do not pop are called papules. These indicate a rash/infection which usually needs treatment. If this is the case in a few days I would pop down to your vet.
Getting some good pictures can be really helpful for your vet also.