My eldest learned to read late, she had to be very actively taught and she learned with agonising slowness. She's only just reading for pleasure at 9+yrs. But she's gone from not having the whole alphabet at 7yrs old to having a mid 7th grade comprehension score on DORA at just over 9 years. So I guess that puts her in a group of kids for whom reading late (and needing to be taught) reflected not her ability to comprehend language but other issues.