Visiting family and my mom is constantly criticizing the way I parent

So we traveled across the country to visit my parents for the holidays. My 2.5 year old son was recently diagnosed with a sensory processing disorder and is starting OT when we return from our trip. When I was explaining it to my mom she basically totally disregarded the diagnosis and the (extensive) testing they did to get to it. At the time I was explaining it my son was calmly playing with the new trucks and car at my in-laws and she basically said "look he's fine right now, nothing is wrong"Now we're a week into our visit, stuck inside in the middle of winter and he's totally overwhelmed with the constant people, being out of his routine and the novelty of new toys has worn off. He keeps screaming out and being loud and she said to him "your mommy is so patient with you, she never changes the tone of her voice how are you ever going to learn to behave".. 🙄... of course the passive aggressive talking through the child. I'm so frustrated that she won't accept the legit medical diagnosis that can explain some of the way he is acting and instead insinuates that he's doing it because I don't yell at him enough. He's a very challenging kid and I felt so relieved to finally get a chance for him to get some help and find ways to make the world easier for him to navigate, but she won't accept that and is instead blaming me. Now I just feel frustrated and we still have 5 days on this trip. I guess I just needed to vent, but if anyone has experienced challenging family or challenging kids I'd love to hear how you handle it! via /r/Parenting http://ift.tt/2DJhIB8