If the student seems to need more practice, will there be additional worksheets available? If not, then what would I do for them to have that additional practice?

Multiple mechanic and grammar worksheets are provided for additional practice in the student workbook for practice.

In regard to writing assignments (not grammar/mechanics worksheets), it is pretty cut and dry. You can repeat any lesson if you feel that it’s needed, and have your child complete the assignment again with a different topic than the one before.