Mary has used a Tu Quoque Argument. This means that she has responded to criticism by accusing the critic of something similar. She has also accused Amy of Attentional Bias meaning that she is only looking for evidence that supports her belief.
I have done my research and concluded based on a surplus of strongly supported evidence presented by reputable doctors and scientists that it is very unlikely that vaccines cause Autism.
But we can't just blindly believe what those doctors say!
That is correct! We can't. But as a community of learners we can go out and look for evidence that either proves or disproves our beliefs and I invite you to do so. There currently is more evidence that proves that there is no correlation between vaccines and Autism.
A friend of mine who vaccinated her child and he developed Autism sent me a link to this website called vaxxedthemovie.com. How do I evaluate whether or not the information on the website and in the documentary is credible?
Well, you can compare it to the other research that you've found. It is important to always check where and who your information comes from. Do the people that created the documentary have any biases or conflicts of interest? Are they considered an expert in the field? Is thee organization reputable?
But so many parents that I've talked to that have children on the Autism spectrum all showed their first symptoms after getting their vaccines. Diagnoses always seem to happen around that time. How could it not be the cause?