I couldn't believe it either. She ticks every point on the standard dyslexia check list.
However, I don't think the old HT really believed in such things and the new HT's last class had DD2 (it was the HT who said she was the best reader in Y2). So I don't think he quite believed the difference.
Like the OP's DD her comprehension is amazing, mainly because she much preferred talking about the book than reading it.
DD1 is very bright (in the proper very interested in, understands what she's taught way), very chatty, very in your face and was completely dizzy.
She was a bit hard work, her quirky edges got her bullied, she's hopeless at making friends, she lost things and the boys capitalized on this by hiding things and making her fuss.
So I think partly the dyslexia got lost in sorting out the social mess and partly I think everyone assumed she'd catch up.
The day she gets her A' level results she probably will have, but the spelling will still be shit.