Meilan Solly in Smithsonian:
In popular culture, Tudor noblewoman Jane Boleyn is often portrayed as a petty, jealous schemer who played a pivotal role in the downfall of Anne Boleyn, the second of Henry VIII’s six wives. According to historians and fiction writers alike, Jane (also known as Viscountess or Lady Rochford) provided damning testimony that sent her husband, George, and his sister Anne to the executioner’s block on charges of adultery and incest in May 1536.
This betrayal—supposedly motivated by her distaste for George and jealousy over his close relationship with Anne—has tainted Jane’s reputation for centuries, with one Elizabethan writer labeling her a “wicked wife, accuser of her own husband, even to the seeking of his own blood,” who acted “more to be rid of him than of true ground against him.”
More here.