From the Admin Dashboard, expand Early Years and select Reports.
Click Report templates.
Select the report you wish to add the box to and click Edit Selected Template
Scroll to the bottom of the report and select the Parent(s) Comment box, as below;
You must update the text for the email template as well, so it adds a link.
Note: You can copy paste the following;
Click the following link if you wish to add any comments, thank you.
This report has now been updated with the parent's comment box.
Note: If you have already assigned the report but not yet sent it to the parents, the reports listed under List of reports left to complete will be updated also.