She was the daughter of Thomas Percival, a member of the Duke's Company for more than a decade.
Her first recorded stage appearance may have been as early as 1681 in D'Urfey's Sir Barnaby Whigg.
Her greatest success was as the main character Lucia in Thomas Southerne's Sir Anthony Love, where Lucia partakes of the freedom of the roistering Restoration rake by disguising herself as "Sir Anthony".
Both men and women in the audience loved her performance in these types of roles.
Her daughter (also named Susanna Mountfort (1690-1720) was an actress at Drury Lane, beginning her career in 1703.