Have you ever been in this situation with a student?

You're helping them with a writing assignment.  They're telling you lots of great ideas, and they are answering any questions you ask them thoughtfully and accurately.  They've clearly got it!  They finish talking and you say "Yes, write that down!"  Their hands hover over the keyboard, then they look back up at you and ask "What did I say?"

Next time you're working with that student, turn on Voice Typing in Google Docs before they start talking.  Then when they're done telling you their ideas, they are in their Google Doc too!  All they have to do it edit.