In Hunters of Dune (2006), the first of Brian Herbert and Kevin J. Anderson's two-part finale to the original Dune series, an ancient knife is discovered on the Atreides homeworld of Caladan that is covered in traces of Paul Atreides' blood.
Hasimir and Margot are raising Feyd and Margot's daughter - whom they have named Marie - as their own in the Brian Herbert/Kevin J. Anderson novel Paul of Dune (2008) [REF].