“People wanted to forget” Valerie Ross Manokey, great-grandniece. Photo courtesy of subject. At age 82, Valerie Ross Manokey knows that her memory is fading a bit. But the retired teacher’s aide in Cambridge, Maryland, who is Tubman’s great-grandniece, becomes animated when recalling bits of family lore. “We know Harriet was born nearby—we say ‘down the…