I can't sound out words there are other ways to work out the missing work. Thank goodness.
Being dyslexia I agree a diagnosis is helpful in understanding how you feel about yourself. It was great to understand why I couldn't read like everyone else. But I was also to of my class at maths there was clearly something not right there.
It's best described as a problem with short term memery. Often people relate it to our reading which is often the case to start with in children, but as you can see on this thread some do learn to read but then still have all the other issues associated with dyslexia.
I did learn to read, but I'm still dyslexic. My working memery or short term memory still doesn't function very well and I still have to work hard every day. Written work is very hard and always will be, thanks to computers though I don't have to form letter that's is really hard work.
Think like this your child is trying really hard just to concentrate on foaming the shape of the letters. With each word, then they have to try and spell the word as well. They can't ever automatically remember this each time they have to think hard to remember. At least typing takes away one process the best thing I ever did was learn to touch type. I could then write without having to think about forming letters it was liberating. I was one of the only children allow to do my course work on a PC, so glad all children have access to this now.
Those that can read remember they also say a dyslexic brain has to work x10 hard to read. It's very tiring even now I find it hard work. I need to keep up my reading practice to keep up my fluency as well or it slips. I'll never be a speed reader but what I am good at is picking incorrect text.
Books with double words anoy me I can't stand tabloyed papers as they as so bad. Often extra words in the text everywhere not everyone will pick these up. But as I read every word I notice evening. If only I was a lot faster I could be a proof reader.
Sorry I've gone off on a tangent, I thought it mite help to see it from the other side. Do get your children tested it does help also look now into how it effects help they can get for exams. When I was at school you had to have had your stament for so many years before GCSE years started to qualify for extra help in exams. I know things have changed but check this out, I had friends who missed out on help as they didn't qualify. It can take time to get these things in place as well, my parents had a right battle with one examination board for extra time and a scibe. Where the others where fine about it.