You have a couple options. You could add a question type that allows File Upload or you could adjust who takes the assessment.
It appears the simplest method would be to add a File Upload question to the assessment if it is a Canvas Quiz. The question could be set to ZERO points and have instructions to take a photo of the handwritten work. Then, each question answered correctly in the handwritten notes could be awarded points throughout the quiz, or the File Upload question could be awarded a total of all the correct points.
Alternatively, Canvas allows you to choose who 'completes' each assessment, so you could take her off the original assessment and then add an assessment where she is the only one assigned, and she'd upload the photo of her handwritten work.