The black sisters Narcisss Malfoy who married Lucius Belkatrix riddle who married Tom Riddle and Druella Lestrange who married Andrew Lestrange all 3 sisters got pregnant at the same time all 3 have birth at the same time narcissa had Draco Druella had Mattheo and bellatrix had Y/N but bellatrix and Voldermort daughter vanished as she was taken all 3 children are powerful as a trio and someone wanted her gone