Rare antique Nantucket family tree watercolor

A rare and important antique Nantucket watercolor of the Obed Marshall family tree signed "Edw. D. Burke pinxt" circa 1800. Framed in a Nantucket made painted frame with its original brass "stirrup" hangers. Original backboard and glass. Bought years ago from 102 Main Street, Nantucket(the home of Obed Marshall). Very good condition with old repair in the upper left. Size: 14.25 x 14.75 inches overall. Sorry, private collection - not for sale