DD6 has similar issues. We do encourage her to use the dictionary. But if she has a writing topic, before she starts to do the actual writing, we ask her in advance to think of the words she might need/want to know. We sit down and go over the spelling while DD writes them down on a piece of "words list" paper. Then when DD is writing the story, she can refer to the "word list" for spelling. Sometimes, the process of making the "word list" is enough to help her learn the spelling for the words and gain some self-confidence in writing.
