Beautiful coastal walk that goes right by the Anchorage by the Sea hotel.
This classic Drakes Island day-camp-day-trip destination is very close to the wedding venue. Perfect easy to moderate morning hike. You'll be done in plenty of time to get ready for the wedding.
Get a little bit of culture in while you're here. The museum houses impressive artwork from the 1800s onward. And they have a sculpture garden! Kids get in for free.