Her hand was sought in marriage even in her youth as a means of alliance with her powerful father.

Suitors included the Intendant of the Court of a Count of the Holy Roman Empire in December 1703, the Elector of Hanover's son (later George I of Great Britain) in June 1706, the Duke of Somerset's son Lord Hertford in 1707–1711, Count Nassau in 1709, and finally Lord Danby (grandson of Thomas Osborne, 1st Duke of Leeds) in 1711, before her father settled on Edward Harley, 2nd Earl of Oxford and Earl Mortimer.

She brought, through inheritance, Welbeck Abbey in Nottinghamshire, Bolsover Castle and Wimpole Hall in Cambridgeshire to her husband.

[3] Their only child to attain maturity was Margaret (1715–1785), and so whilst Margaret inherited most of the combined Holles-Harley fortunes on her parents' deaths, the title of Earl of Oxford and Earl Mortimer passed to Edward's cousin (also Edward).

[5] The general area was owned by the Harleys and developed during their lifetimes, hence other streets are named after their family, too.