good reader/poor speller

[BLANCA]

why would a child with reading age of 16+ (age 10) only be a little above average for spelling? when I ask teacher he just shruggs & says it will not affect dd's performance in exams. I am not so sure as we are in herts with part. selective schools. The tests are standard form so surely bad spelling will be reflected in results? Has anyone else had this problem or know for sure if it will affect herts vr test results? Also any ideas on improving spelling? DD is in top group and always gets good score in weekly test, but in day to day work, or if I ask her to spell word from test of maybe two weeks ago I see lots of mistakes. also on parents evenings lots of red pen to correct spellings. Why do school not see this as a problem? Am I just being O.T.T?

many thanks