Biology doesn’t make you a parent. Love does. Cathy Jackson, 48, of Spencerville, keeps on proving that. “From day one, they called me Nana,” Cathy said of 9-year-old Mia and 8-year-old Jeanel. “I told them a Nana takes the place when Mommy can’t be there.” Two years ago, Cathy and her husband, Tim, began taking care of Mia and Jeanel, when their friend and Tim’s co-worker, Robert, had a massive heart attack. They invited Robert, a single father, to recover in his home.