What would you do if you saw a mom bring a teenage boy into the female bathroom

I always thought it was common sense that if a mom(or dad) is bringing a teenager of the opposite sex into the bathroom that means they may have some type of disability. That's what I always assume. But today a mom was doing that and a couple women in the bathroom started screaming at her that he couldn't be in here. She was trying to explain but they kept screaming and she finally yelled "HE HAS AUTISM!!! I'M JUST TRYING TO CHANGE HIM!!!" She had tears in her eyes and one of the ladies rolled her eyes. The mom also had a baby so I offered her some help and held her baby while she handled her autistic teenager. I just figured it was common sense. It really sucks that we don't have more family bathrooms for situations like this because this mom was in tears