Exactly. They are different and should not be "autism". Technically my kid is not non-verbal but limited to one or two words, like if he wants to watch blue's clues he'll just say blue or if he's hungry he will just say yum yum.
I'm not a doctor but you and your niece have different conditions and likely have different causes and potentially different treatments. We should eliminate the word autism and separate it into like 5 or 10 different conditions and study them separately.
He was an asshole so he should be used to shit. Same guy one year, the company sponsored a "Thanksgiving dinner", he told one of my coworkers, who was admittedly overweight like 300-350lbs "wait till everyone else gets a plate before you eat everything"