She was a patron of schools and craftsmen and also played an active role in legal affairs pertaining to the Ormond estates.

James Graves in his History of the Cathedral Church of St. Canice, Kilkenny says she was "unquestionably one of the most remarkable women of her age and country".

In 1528, Margaret's husband was persuaded to renounce his Ormond title in favour of one of his rival claimants, the 7th Earl's grandson, Sir Thomas Boleyn, whose daughter, Anne Boleyn was being courted by King Henry VIII with the purpose of making her queen consort.

Aided by Cardinal Thomas Wolsey Piers was compensated for his loss of title by being made 1st Earl of Ossory that same year (1528).

[20] She urged Piers to bring over skilled weavers and artificers from Flanders and she helped establish industries for the production of carpets, tapestries and diapers (a type of cloth).

Richard Stanihurst described Margaret as having been "manlike and tall of stature, liberal and bountiful, a sure friend and a bitter enemy".

Reverend James Graves said of her: "The fairest daughter of the Earl of Kildare was unquestionably one of the most remarkable women of her age and country".

[21] Another chronicler considered her "a lady so politic, that nothing was thought substantially debated without her advice",[22] while another described her as "able for wisdom to rule a realm had not her stomach overruled itself".

[7] Margaret also developed a personal estate on her jointure lands, which eventually descended to her younger son, Richard, 1st Viscount Mountgarret.