Parece que seus esforços no final da guerra foram o suficiente para tirá-los da armadilha com Wiki de Harry Potter dizendo:
Because he and his family defected from the Death Eaters they were pardoned for their crimes after Voldemort's final defeat and did not serve a stint in Azkaban. He and Narcissa later had a grandson, Scorpius Malfoy, after Draco married Astoria Greengrass.
Ênfase minha.
Como Jenaya aponta nos comentários, o wiki de Harry Potter pode não ser o mais confiável e, portanto, usar seus link para a página de Pottermore sobre Draco Malfoy , podemos encontrar mais apoio:
Following the battle, his father[Lucius Malfoy] evaded prison by providing evidence against fellow Death Eaters, helping to ensure the capture of many of Lord Voldemort’s followers who had fled into hiding.
Um pouco de informação extra sobre suas vidas depois vem do parágrafo final sobre a vida de Draco:
Parece que enquanto os Lúcios e Narcisa se voltaram contra os Comensais da Morte no final, eles não se tornaram mais tolerantes com os trouxas ou meio-sangues no processo.Draco married the younger sister of a fellow Slytherin. Astoria Greengrass, who had gone through a similar (though less violent and frightening) conversion from pure-blood ideals to a more tolerant life view, was felt by Narcissa and Lucius to be something of a disappointment as a daughter-in-law. They had had high hopes of a girl whose family featured on the ‘Sacred Twenty-Eight’, but as Astoria refused to raise their grandson Scorpius in the belief that Muggles were scum, family gatherings were often fraught with tension.