Help…my dd is having trouble with Spelling Wisdom

Hi everyone.  We seem to be having some difficulty with Spelling Wisdom.  My dd just turned twelve and has had some reading/spelling difficulty.  I have tried using Spelling Wisdom with her over the past few months, but I don’t think we’re doing something right (or it’s maybe too difficult for her??).  With the beginning, shorter passages I wrote the passage on a white board, had her examine it, talked about tricky spellings/rules and then erased it when she thought she was ready to write it.  This didn’t go too badly, but when the passages started getting a bit longer I switched to having her write the entire passage every day (more like copywork) and then, on the last day of the week, I dictated it to her and had her write it.  The problem was that she was still making a few errors on the piece, even after writing it for three days or so.  Should I expect this?  Should she re-do this passage the following week?  Is she not ready to do this and I should stick to copywork?  Thanks for any advice.

Rachel H.