I can understand why it would be hard to hear, though honestly man I wouldn't take it personally. Research has shown that people make their 'first impressions' about people they meet in the first 7 seconds... That's not a huge amount of time, in fact for people on the spectrum that's probably half the time it'd take for us to decide on how to say hello.

The up side which you should try to focus on is that this person looked past their early judgements and got to know you and then was worried that she'd upset you by telling you about her first impressions.

A story my mum always tells me about first impressions is that when she first met my dad (she was working in a pub and he was on shore leave from the RAF) she thought he was a loud, immature, military idiot. She ended up marrying him and being married to him for over 25 years until my father died. First impressions are only that, impressions. They can't possibly tell you anything about the person that actually matters.