For anyone seeing the above post from 2002 about Margaret Tilbury, note that the post also mentions the Decker surname. This would suggest that Margaret Tilbury is from the line of Richard and Jane Tilbury/Van Tilbury, whose dau Mary married a Decker, probably Cornelius Decker from what I can see. Margaret could be a dau of one of Richard and Jane Tilbury's sons. Records of the Riverside Cemetery in Union, Broome Co. NY
http://www.rootsweb.ancestry.com/~nybroome/rivrside/riverfe.... and other Broome Co. records might be helpful here.