OP, sounds like spelling is a huge issue for your daughter. What have you already tried with her?
I have had really good success as a tutor with the workbooks from the abecedarian company. They are easy for parents to use (without the teacher manual) and relatively inexpensive. Depending on her issues you would start with either workbooks B1 and B2 (or B if you feel she can move more quickly -- honestly I'd just get B1 and B2 and have her move rapidly), then C, the "Spelling Patterns". Book D is for spelling words with Greek/Latin origin and she'd probably not need that.
http://www.abcdrp.com/