She was the daughter and sole heiress of Colonel Henry Beekman and his first wife, Janet (Livingston) Beekman. She was married in 1742 to her cousin, Robert Livingston. The family estate was burned by the British in 1777 and was rebuilt by Margaret between 1779-1782.

Her death notice appeared in The Poughkeepsie Journal, July 8, 1800.

"On Tuesday, of last week, the 1st of July instant, Mrs. MARGARET LIVINGSTON, the widow of the late much respected and much regretted Judge LIVINGSTON, was about 2 o'clock, P. M. taken with a faintness, in a few minutes she requested assistance to help her to her bed, which was the last she spoke ; before evening her spirit was fled. There have been few professors of the Christian religion, who in so eminent a degree from their lives, practice and conversation, have evidenced the reality of a change wrought in the human heart by its salutary operations.

This good Lady had on the morning of the day on which she was kindly taken to her Father's house, in a manner for which few examples are to be found, exercised her benevolent christian-like disposition—she had for a number of years supported or relieved a considerable number of indigent persons, among the rest, her former slaves whom she had manumitted, on the 1st day of July annually, these pensioners on her particular bounty, came to receive at her liberal hand the sums or stipends her charity prompted her to bestow, and which their necessities required. After having spent the morning of that day, in this god-like exercise of relieving the wants of the poor, it appears her saviour had no further work for her to do in this world—And like a sovereign who has a right to dispose of all creatures and things in his goodness and wisdom he sees fit, took her from usual health, strength and spirits—without sickness and almost without a groan from this world of probation, to a scene where sin and sorrow never enter."

A cenotaph was erected to her memory within the Rhinebeck Reformed Church in Rhinebeck, New York.

Margaret is recognized as a female patriot by the Daughters of the American Revolution (DAR) for her patriotic service including paying the supply tax in 1779.