How can I share a link to a folder on a Time Capsule drive?
Have you tried something like


afp://gator._afpovertcp._tcp.local/Data/Test


It's general with the following terms....


afp://TimeCapsule._afpovertcp._tcp.local/Data/Test


This would work for a Time Capsule with name TimeCapsule and a Folder Test inside the drive named Data (I added the emphasis for clarity - you'll want to simply send the link in plain text)

You can get this by dragging the folder to your Finder sidebar and then looking in the Info window for that item.