Sentence Structure

Today I graded a student's essay. The paper left me frustrated. The assignment was to write a persuasive essay complete with a thesis. The essay did not have a thesis, and therefore was not persuasive. This, however, was the least of the problems with the paper. The paper lacked cohesive sentences. Thoughts were chopped up and blended together into a puddle of words on the paper. I am really concerned for this student. I wonder how she got this far writing at this level.

I pulled the student aside today and asked her if she could meet me during study hall tomorrow to talk about her essay. She agreed. I want to intervene to help this student move forward in her academic and writing endeavors, but I do not know where to start. I pulled some explanations from a grammar workbook on sentence structure. The activities focus on defining what a sentence is and identifying and correcting fragment and run-on sentences. I want to be careful not to overwhelm the student, though. I can only imagine that writing was hard for her to begin with.

Is a grammar lesson the best approach? How else do I get her to see and understand what the problem is? Should I start with her paper instead and see if she recognizes the problem? I am really confused. I know there may not be a magical, overnight solution to her writing difficulties, but I am eager to help. I just don't want to take the wrong approach and risk losing her altogether.