Sarah Denormandie Peter Abercromby [1790-1806] was a daughter of Anthony Denormandie, Esquire and Mary Hall. Her parents were residents of Philadelphia at the time of her marriage to John Joseph Abercromby on 7 January 1791 at Pon Pon Parish near Charleston, South Carolina, according to her marriage certificate. John and Sarah were married by the French Huguenot Church minister of Charleston, Jean Paul Coste, at the Smith Hall plantation of Pon Pon Parish, South Carolina.

Sarah's birth and death dates are unknown.

Sarah had previously been married to Christopher Peter (?-1790), a planter in St. Paul's Parish, South Carolina. He was one of the patriots the British exiled to St. Augustine after Charleston fell to the British in 1780. In February 1782, with Charleston occupied by the British, the rebellious General Assembly of South Carolina met in Jacksonborough, and Christopher Peter was one of seven men representing St. Paul's Parish of Colleton County.

Christopher Peter's will, dated 20 August 1790 and proved 1 March 1791, mentioned his wife Sarah and daughters Elizabeth and Mary [under age], his brother, Thomas Smith and his children: William, Thomas, Jane and Morton Wilks Smith, as well as Peter's lands west of the Edisto and Pon Pon Rivers and his Cherry Valley Plantation. Peter's will also stated that "it is the earnest request of their father that his children may not be admitted by the executors ... to go to the Northward or out of this State."

But soon after their marriage, which took place two months before Peter's will was proved and four months after he had made it, Sarah and John Abercromby went to Bristol, Bucks County, Pennsylvania where on 10 September 1791 they purchased 145 acres in Bristol from Dr. John Abraham Denormandie of Burlington, New Jersey. But a year later, on 17 September 1792, John Joseph Abercromby and his wife Sarah conveyed the Bucks County, Pennsylvania property back to Dr. Denormandie.

John and Sarah Abercromby’s son, Alexander, was baptized on 9 December 1792 at St. Michael's Church, Trenton, Mercer, New Jersey, just across the Delaware River from Bucks County, Pennsylvania.

Three of their children were baptized at St. Paul Protestant Episcopal Church, Baltimore, Maryland. On 14 May 1797 their daughter, Ernestine, was baptized there with her birth date recorded as 16 September 1792. Their son, John Joseph Abercrombie, Jr. (1798-1877), was baptized there on 3 June 1798 with his birth recorded as 4 March 1798. And their son, James Abercrombie, was baptized there on 27 October 1799 with his birth recorded as 16 March 1799.

Catherine Abercromby, who was buried from St. Philip's Parish, Charleston, South Carolina on 21 June 1800, may have been their daughter also because by 27 November 1800 John and Sarah Abercromby were back in Charleston, South Carolina where they sold “a Negro fellow named Radcliffe formerly belonging to Christopher Peter” to Gil Pierre Bournonvivier, a Catholic priest.

On 29 August 1804 John Abercromby sold 1,000 acres in Horry County, South Carolina on the Waccamaw River, which had been granted to James Abercromby in 1735, to Archibald Taylor, a Georgetown merchant, with Sarah Abercromby renouncing her dower.

In 1806 "Mrs. Sarah Abercrombie" was listed in the Charleston, South Carolina city directory living at 9 Berresford Street [now Fulton Street].

In 1808 the Charleston [South Carolina] Times ran an ad for a remedy for worms that included a testimonial letter from John J. Abercromby of No. 28 Bridge-street, Baltimore.

Little is known of the family in later years. According to a letter written by their daughter Ernestine from Philadelphia on 23 February 1874 to "My dear Brother," the family must have moved to Tennessee at some point. The letter says, "As respects our Father's family all the principal papers were lost on the road when we moved from Richmond to Nashville, and Murfreesborough."

John and Sarah's son, John Joseph Abercrombie, Jr. (1798-1877), who served in the Mexican War and was later a Union general during the War between the States, is thought to have entered West Point from Tennessee, graduating in 1822. General John J. Abercrombie, Jr. is buried in the Woodlands Cemetery at Philadelphia. His sister Ernestine wrote letters from Philadelphia to her "brother" in 1871, 1874 and 1889 when she was elderly.