Phew! Caught up at last! I've been trying to read all the posts so I could join in with the late dyslexia discussion but it's all moving too fast!
Anyway we are going through that now with dd. A good friend of mine is studying for a masters which will qualify her to carry out dyslexia assessments. She asked if she could assess dd as part of her coursework because of her low English grade compared to maths and science.
I wasn't expecting her to find anything really but in the initial assessment she scored her as definitely warranting further assessment.
She thinks we should speak to college about her using a laptop or extra time. Dd is thinking about it.
With her it's not really reading or spelling. It's word recall and speed. She gets her words muddled when talking and it's worse when she's anxious. She's always been the same and was a very late talker.
I totally get the bad mother thing. All that stress last year about English language. Extra time would have made so much difference. 
She was assessed in y6 but they said she performed too well for the tests to measure anything. The tests were for 7-11 year age range and she was a bright 11.5 yo at the time.