Rachel Wriothesley, born in 1636, was second daughter of Thomas Wriothesley, Earl of Southampton, by his first wife, Rachel de Ruvigny, of an ancient Huguenot family. Her mother died during her infancy. An elder sister, Lady Elizabeth, married Edward Noel, son of Viscount Campden, afterwards Earl of Gainsborough. Lord Southampton married twice after his first wife's death, but he had only one surviving daughter by his second marriage, who being heiress of Sir Francis Leigh, afterwards Earl of Winchester, the whole of the Southampton property was left to the children of his first marriage, who thus became considerable heiresses. Lady Rachel, when yet young, married Francis, Lord Vaughan, eldest son of the Earl of Carberry, but it was an alliance rather of acceptance than of choice on either side, and the early death of Lord Vaughan left her free to marry again. All we know is that she possessed the love and attachment of her husband and the respect of his family. They had one child who died in infancy.

In 1667, on the death of her father, she inherited the estates of Stratton, but she passed most of her time with her beloved sister, Lady Elizabeth Noel, at Tichfield, in Hampshire. There she became engaged to Mr. Russell, younger son of the Earl of Bedford. They were married in 1669, but she still retained the name of Vaughan till in 1678, on the death of his elder brother Francis, William succeeded to the courtesy title of Lord Russell, when she assumed that of Lady Russell.

Lord Southampton, her father, was a man of high character and great influence. During the civil troubles he took no very decided part until after the misfortunes of Charles I., when his loyalty overmastered all other feelings. In the first disputes between the king and the parliament he disapproved of the high-handed measures of the Court, and, disliking the government of Strafford and the principles of Archbishop Laud, he was considered to be one of the peers attached to the popular cause. But, like Lord Falkland, he could not heartily join the party opposed to the king, whom he accompanied to York and to Nottingham. He was at the fight at Edgehill, and thence went to Oxford, where he remained with the Court during the rest of the war. He was hopeless all along of the success of the royal cause, and was ever the strenuous and unwearying advocate of accommodation and peace. When the execution of the misguided king took place, he was one of the four faithful servants who obtained permission to pay the last sad duty to his remains. From that time he retired to his seat at Tichfield, taking no further part in public affairs. When Cromwell rose to supreme power he greatly wished to meet Lord Southampton, but the meeting was avoided by the earl, and he continued in retirement. His daughter was educated on strict Protestant lines, with every predilection for the doctrines which her mother's family, professing a faith persecuted in their own country, were likely to encourage. Southampton, though attached to the Church of England, was most tolerant towards Dissenters, so much so that Clarendon in his History, while describing him as "a man of exemplary virtue and piety, and very regular in his devotions," says, "He was not generally believed by the bishops to have an affection keen enough for the government of the Church, being willing and desirous that something more might be done to gratify the Presbyterians than they thought right." This spirit of her father was probably the source of the Christian charity as well as piety of Lady Rachel's life, appearing in her letters and animating her whole conduct. Or rather we may say, that both father and daughter were influenced by the old Huguenot principles and connection.