When she is reading, encourage her to OBSERVE how words are spelt, and maybe even compile her own list or 'dictionary' of words she knows she has difficulties with.
But the main thing is to UNDERSTAND how Phonics and spelling 'works', and to try to remember the main 'rules'. This book could help a lot:
An inexpensive and easy to use book, that can encourage children with reading, spelling and writing, and really help them to understand Phonics, is reviewed in the MN Book Reviews section. Just search ‘Phonics’ and my name.
Using "spelling voice" to pronounce the word very precisely then ask her to divide the words into syllables then look at each syllable carefully to identify any parts that are particularly tricky and try to relate to other words she knows.