Thank you for your thoughtful question.
I think the best suggestion I can give is to use dots 456 for vertical lines that separate columns in a division arrangement. Pages 13–29 through 13–40 of the Provisional Revised Nemeth Course Manual, posted by NFB will give you more tools to transcribe your children's material from print.
I do believe that Provisional course is a great tool for you to become informed about the Nemeth Code in preparation for your oldest moving into HS. As you study through it, please allow yourself time and regular breaks from studying; it's a dense book.
We look forward to getting more questions from you as you continue your journey.