Good luck! I agree with you on the second opinion if the first opinion doesn't sit right.
Kriston,
DD8 really liked doing that mirror writing and I can't remember if she was late 6 or 7. She has absolutely no vision issues, she just thought it was cool that she could do it. She would mirror write paragraphs and paragraphs for fun.
DD6 did do the letter reversals, but it's pretty common for the age group, so it kind of doesn't confirm anything one way or another. I think it would be a combination of red flags combined with your mommy gut.
You've got great instincts.
