I am not a parent, but I am an Uncle (or I call myself non-binary Aut-Uncle) and so much of what you say resonates with me. I remember being in sensory overload last year when my brother was sick, but my nephew wanted to come over and he vomited. I had just been to see a doctor and my father had brought my mother her lunch and she wanted me to give it to her (she's disabled with MS). The smell of my nephew's vomit was strong, and I had a mask on, which my mother found offensive, and I told her that I was in sensory overload. Then, when my father arrived home, I had done a load of washing, and he threw the shorts that my nephew had been sick on in with the clean washing, so I had to redo it! Okay, it wasn't malicious, but I was annoyed.

As much as I love my nephew, I need regular sensory breaks if he's around for more than a few hours.

A lot of sympathy is garnered for parents of autistic or disabled kids, but one thing that is not considered is, sometimes neurotypical kids of disabled parents can be intuitively adaptable.