With dogs, vaccine reactions are relatively rare. Cats have a very small risk of developing vaccine related cancer at the site of certain injections, but the risk is so minimal that it does not compare to the risk of the diseases you are preventing. Vets also take precautions to minimize risks, such as giving vaccines lower on the legs so that if there is the off chance of a reaction, it is easier to deal with.
The vet will be able to age your puppy fairly well. Boostering of shots can be very important. If shots are not boostered at the appropriate time, the body never mounts an appropriate response to the pathogen and you are basically left with an immune system that is the same as not being vaccinated at all.
I would definitely recommend a trip to the vet for your puppy. It seems as though she may be special needs with her background.
And believe me, vets are not just in it for the money. With the amount of time and money put into school, most vets do it for the animals. Many vets make very little money per year and they tend to owe large amounts of debt for their schooling. Basically the veterinarian salary had not increased at the same rate as the cost of schooling and it means most vets live in large debt.
Yes, Her background could of been better. The world wants money, Vets can be a different story as you mentioned
As for the reactions I do know dogs who have had major reactions but eh...different places ...different dogs..different vets.