Hi Sarah,
I have worked with a lot of children who have had difficulty in
reading and related skills and typically their reading accuracy and
comprehension would improve well before their spelling (spelling was
always improving, just at a slower rate). Llike Emma said, they really
need to understand that spelling is all about understanding that words
are made up of sounds and these sounds are represented by letters and
the rules that apply to different combinations. There is a great
program called Spelling Mastery that I usually recommend parents use
to continue working with their children after they had left the
reading clinic. Spelling Mastery is a direct instruction program and
it has a scripted teacher's book so that all you have to do is read
the script and your child can follow on in the accompanying work book
(as well as listening exercises). Unfortunately Spelling mastery is
expensive (the teacher's book is about $200, the workbook about $20)
but your local library might have it and many schools have it too so
you could hopefully borrow the teacher's book and just buy the student
workbook. Sorry to suggest such an expensive option but it really is
so easy for parents to follow the script and know that they are doing
the correct procedure. There are plenty of other spelling programs on
the market, just avoid anything that groups words into themes, the
emphasis should be on letter sounds and building on the rules of
spelling.
Good luck!
Fiona