Shortly after Voldemort's downfall, Bellatrix tortured Frank and Alice Longbottom to insanity, thinking they had information on Voldemort's whereabouts. Somewhere after her childhood but before Voldemort's downfall one of Bellatrix's sister, Andromeda would have had Tonks with her husband, Ted Tonks. Her marriage would also have happened early on. Bellatrix, Rodolphus, Rebastian ( her brother in law ) and Barty Crouch Jr were all caught and sentenced to life imprisonment in Azkaban. As said in the book, Bellatrix did not try to defend herself but sat on her chair like it was a throne and stated that the Dark Lord would return.