She went to school at Mrs. Hayward's seminary, and later to Mr. Kirk. She also attended a dancing-school that gave exhibitions of the grace and proficiency of its pupils in the parlors of the Union Tavern in Georgetown. At one of these exhibitions Margaret was crowned by Mrs. Madison, the wife of the President, as the prettiest girl and most graceful dancer in the room. Naturally ambitious, this first social triumph pointed out the possibility of greater ones, to be achieved only after bitter contests that would have crushed the spirit of a more sensitive woman.
Her father deeming her sufficiently well educated, in which opinion she concurred, she quitted school in her fifteenth year, and, being now a young woman of bewitching beauty and abundant leisure, she entered extensively upon her career as a belle.
Two young military men whom her fascinations had ensnared were at one time on the point of a duel. With one of them, Captain Root, she had planned an elopement, and was actually about to descend from her window when she accidentally overturned a flower-pot: this crashing on the ground below, roused her father and put an end to her flight. More than that, her indignant parent carried her off to New York, where he left her under the wing of his old friend Governor De Witt Clinton, to go to Madame Nau's school. Clinton was very severe with the spoiled little beauty, and the staid atmosphere of his home was not congenial to her. She wrote her father very homesick letters, in one of which she promised that if he would take her home "neither Root nor branch should ever tear her from him." Her wit greatly pleased him, and after he had passed the bon mot around among his guests and his Peggy's admirers, he went to New York and brought her home.
It has been said that she was not yet sixteen when from a window of her father's tavern she for the first time saw John Bowie Timberlake, as he passed along Pennsylvania Avenue on horseback. Their acquaintance, engagement, and marriage followed within the space of a few weeks.
Several years of quiet happiness ensued, during which three children, a son, who died in infancy, and two daughters, were born to them.
Timberlake was a purser in the navy, and when he was ordered to sea duty he closed his little home, and his wife and children went to her father's to stay during the time of his absence. He died of asthma aboard the "Constitution," at Port Mahon.
His widow shortly afterwards married General Eaton, who was at that time a United States Senator and a guest at her father's house. For the first time the little Peggy O'Neill, of triumphant dancing-school days, felt that her foot was actually upon the rounds of the social ladder. John Quincy Adams was President at the time, and one of the bitterest Presidential campaigns this country has ever witnessed had just drawn to a close in the election of Jackson. One victim of the freedom of press and speech, everywhere indulged in, was the wife of the President-elect. Her gentle soul, stung by the breath of slander, which all the vigilance of a devoted husband had been powerless to avert, had passed unregretfully from earth. Jackson came to Washington a bereaved and embittered man.
There was a puritanical tendency among the women who made up the society of that era, and to whom Margaret O'Neill appeared as the embodiment of a sport-loving element that prevailed among men.
Life had a rural quality in those days which it has since lost. Horse-racing was universal, and the great race between Eclipse and Sir Henry, run on Long Island May 27, 1823, for a purse of ten thousand dollars, was a national event. Hundreds of thousands of dollars had been staked, and Peggy O'Neill no doubt was intimately acquainted with some of the heaviest winners and losers, among the latter of whom was John Randolph. Though she was far too young to remember the opening of the first race-track in Washington, November 3, 1803, she was yet familiar with all the details of its inauguration, on which occasion both houses of Congress had adjourned, the Senate to have the ceiling repapered, and the House, which was apparently less resourceful, because it had no pressing business on hand.
Growing up in a public house, she was undoubtedly familiar with much in the lives of men of which other women of her day, leading more secluded lives, feigned ignorance. Yet she had become in no way contaminated by the liberal atmosphere she had breathed from infancy.