Presumably born in The Hague, Joanna was the second child of Duke Albert I of Bavaria (1336--1404), by his first wife Margaret (1342--1386), a daughter of the Piast duke Louis I of Brzeg. Her siblings included Count William VI of Holland, Johanna Sophia of Bavaria and Margaret of Bavaria. _Her_ paternal grandparents were Emperor Louis IV and his consort Countess Margaret II of Hainaut. <sep>, Pronoun: Her <sep>, A: Johanna Sophia <sep>, B: Margaret of Bavaria