hi branwen
your DD sounds like my DD5. Her average WPPSI subtest scores was 16.8 and got a FSIQ of 147 but can't read a lick! ... she is also a montessori kid and completely avoided the reading/phonics area of the class.. just did the minimum (learning sounds of letters).. I would love to know what you discover- my DD has had routine "quickie" eye tests and has normal vision but maybe there is a subtler problem.
irene