Helping means they hold the pencil. Doing it for them just means you hold the grade.

Help is measured by what the other person can do afterwards. If you are holding the pencil then you are the one practising, and they get a finished page with none of the learning inside it, so next week the same problem stops them again. Doing it for somebody feels generous and quietly removes the work from them. The uncomfortable pause while they try is the part that teaches.

Sit on your hands and ask questions instead. What comes next, where did you get stuck, what does that word mean. Let them write every line, slowly.