You may want to update your supporter's personal message to the participant.
How to get there:
You'll be on the Campaigns window of the Control Panel.
Choose the campaign's name or the edit link to the right of it.
What to do:
Click on the Supporter tab.
Scroll down to the name of the supporter you’d like to make changes to, or enter their last name in the search box.
Click on the first action item, the Edit button (pencil icon) adjacent to the name.
Enter the desired text and click Save.