start with a spelling notebook
That is excellent if she is already writing her letters correctly. Yes, now you want to focus on proper structure of words and sentences (when she is ready). I would begin to create a notebook of spelling words at her level. She can then use those words to create sentences. Make it simple. Teach her declarative sentences first, then the others.
The way to create the notebook is to find words at her level then say the word to her have her repeat the word, then ask her to say and write sound by sound the phonograms. For instance you say, "the word is "shut". You ask her to repeat the word. Then ask, "What is the first sound you hear in the word "shut"? She should say "sh". Then have her write it. and so on until the word is complete. Then she reads her completed word. This is how it is done in Spalding. Hope that helps and doesn't confuse you.