You have to backtrack through Goat Island.

No direct path exists. Three Sisters Islands are connected to each other and to Goat Island by small footbridges. Terrapin Point is on the opposite end of Goat Island, near Bridal Veil Falls. To get there, you walk back across the bridges, cross Goat Island, and head to Terrapin Point. It’s not a long walk—maybe 15 minutes—but you cannot cut across the water.