She's gone by many titles over the years.
At one point she was second lady – although she preferred captain of the vice squad, thank you very much. She’s also been known as prankster, professor, wife, mom, gran and, more recently, protector-in-chief.
And it’s the last one that surfaced again this year when Jill Biden shielded her husband, Joe Biden, from hecklers as the couple campaigned across the US for Joe to become president.