In 1817, her Father died in South Africa, where he was serving as the colonial secretary at the Cape of Good Hope. His family was left virtually penniless. Prince Frederick, Duke of York and Albany, an old friend of her grandfather's, arranged for Caroline's family to live at Hampton Court Palace in a "grace and favour" apartment, where they remained for several years.

In 1827, Caroline married George Chapple Norton, barrister, M.P. for Guildford, and the younger brother of Lord Grantley. Norton was a jealous and possessive husband, given to violent fits of drunkenness, and the union quickly proved unhappy due to his mental and physical abuse of Caroline. To make matters worse, Norton was unsuccessful in his chosen career as a barrister, and the couple fought bitterly over money.

In spite of his jealousy and pride, Norton encouraged his wife to use her connections to advance his career. It was entirely due to her influence that in 1831 he was made a Metropolitan Police Magistrate. During these years, Caroline turned to prose and poetry as a means of releasing her inner emotions and earning money. Her first book, The Sorrows of Rosalie (1829), was well received. The Undying One (1830), a romance founded upon the legend of the Wandering Jew, soon followed.

Due to her dismal domestic situation, Caroline became passionately involved in the passage of laws promoting social justice, especially those granting rights to married and divorced women. Her poems "A Voice from the Factories" (1836) and "The Child of the Islands" (1845) centred on her political views.

While Caroline fought to extend women's legal rights, she wasn't involved in further social activism, and had no interest in the 19th-century women's movement with regard to issues such as women's suffrage. In fact, in an article published in The Times in 1838, countering a claim that she was a "radical", Caroline stated: "The natural position of woman is inferiority to man. Amen! That is a thing of God's appointing, not of man's devising. I believe it sincerely, as part of my religion. I never pretended to the wild and ridiculous doctrine of equality."

Primarily because of Caroline's intense campaigning, which included a letter to Queen Victoria, Parliament passed the Custody of Infants Act 1839, the Matrimonial Causes Act 1857 and the Married Women's Property Act 1870. Her most recent biographer Diane Atkinson notes that unlike in 1839 and 1857, Caroline played no part in the campaigning for the 1870 Act. Under the Custody of Children Act legally separated or divorced wives, provided they had not been found guilty of Criminal conversation, were granted the right to custody of their children up to the age of seven, and periodic access thereafter. The Act applied in England, Wales and Ireland only. While Caroline could have hoped for custody of her youngest son, and access to her older sons who were seven and ten when the Act was passed into law, her husband insisted that her sons stay in Scotland.

Caroline is said to have had a five-year affair with prominent Conservative Politician Sidney Herbert in the early 1840s; however, Herbert married another woman in 1846. In middle age, she befriended the author George Meredith. She served as the inspiration for Diana Warwick, the intelligent, fiery-tempered heroine of Meredith's novel Diana of the Crossways, published in 1885. Caroline finally became free with the death of George Norton in 1875. She married an old friend, Scottish historical Writer and Politician Sir W. Stirling Maxwell in March 1877. Caroline died in London three months later.

Caroline was soon faced with an additional tragedy; the death of her youngest son, william, in 1842. The child, out riding alone, suffered a fall from his horse and was injured. According to Caroline, the child’s wounds were minor; however, they were not properly attended and blood-poisoning set in. Norton, realising that the child was near death, sent for Caroline. Unfortunately, william died before she arrived in Scotland. Caroline blamed Norton for the child's death, accusing him of neglect. After William's death, Norton allowed Caroline to visit their sons, but he retained full custody, and all of her visits were supervised.

In 1849 Daniel Maclise finished his fresco of Justice in the House of Lords, for which Norton had modelled. He chose her because she was seen by many as a famous victim of injustice. Caroline's old friend, Lord Melbourne, opposed the reforms she fought for. He was scolded for his opposition by Queen Victoria; the Queen wrote that he defended his actions, stating: "I don't think you should give a woman too much right...there should not be two conflicting powers...a man ought to have the right in a family."

In 1854, her remaining son, Thomas Brinsley Norton, married a young Italian, Maria Chiara Elisa Federigo, whom he met in Naples. Thomas also suffered from poor health, and spent much of his life as an invalid, reliant upon his mother for financial assistance. Despite his ill health, he lived long enough to succeed his uncle as 4th Baron Grantley of Markenfield. Lord Grantley also predeceased his mother, dying in 1877.

When Parliament debated the subject of divorce reform in 1855, Caroline submitted to the members a detailed account of her own marriage, and described the difficulties faced by women as the result of existing laws.

The Act gave married women, for the first time, a right to their children. However, because women needed to petition in the Court of Chancery, in practice few women had the financial means to petition for their rights. The Matrimonial Causes Act reformed the law on divorce, amongst others making divorce more affordable, and established a model of marriage based on contract. The Married Women's Property Act 1870 allowed married women to inherit property and take court action on their own behalf. The Act granted married women in the UK, for the first time, a separate legal identity from their husband.

His son, John, inherited the title and estates. The 5th Lord Grantley was a numismatist, and a Fellow of the Society of Antiquaries of London, the Royal Numismatic Society and the British Numismatic Society. He assembled a large collection of coins and also grew orchids. Caroline Norton's grandson caused a scandal in 1879, when he ran off with another man's wife, the former Katharine McVickar, daughter of a wealthy American stockbroker. The jilted husband was the 5th Lord Grantley's older cousin, Major Charles Grantley Campbell Norton. Katharine's marriage to Charles was annulled, and Katharine and John were married that November, five days before the birth of their first child. Despite her scandalous introduction to British society, Katharine went on to become a successful London hostess.

The combined beauty and accomplishments of the Sheridan sisters led to their being collectively referred to as the Three "Graces". The eldest sister, Helen, was a Songwriter who married Price Blackwood, the 4th Baron Dufferin and Claneboye. Through her, Caroline became the aunt of Frederick Hamilton-Temple-Blackwood, 1st Marquess of Dufferin and Ava, who later served as the third Governor General of Canada and eighth Viceroy of India. Her younger sister, Georgiana, considered the prettiest of the three, later became the wife of Edward Seymour, 12th Duke of Somerset.

During the early years of her marriage, Caroline used her beauty, wit, and political connections, to establish herself as a major society hostess. Caroline's unorthodox behaviour and candid conversation raised more than a few eyebrows among 19th-century British high society; she made enemies and admirers in almost equal measure. Among her friends she counted such literary and political luminaries as Samuel Rogers, Edward Bulwer-Lytton, Edward Trelawney, Abraham Hayward, Mary Shelley, Fanny Kemble, Benjamin Disraeli, the Future King Leopold I of Belgium and william Cavendish, 6th Duke of Devonshire.