Robber’s Wine by Ellen Hart

Winner of the Lambda Literary Award for Best Lesbian Mystery. Wealthy Belle Dumont vanished from her home in the Minnesota woods only hours before she was to reveal startling news to her three grown children. The kids and Belle's lover deny any knowledge of this mysterious bombshell, but amateur sleuth Jane Lawless, Belle's old friend, suspects these charming folk of being less than forthright. In fact, Jane suspects cold-hearted murder.