Leo van de Pas' has this couple on his website as:
Lady Frances Cecil b. est 1581 d. 12 Jun 1653
Sir Nicholas Tufton, 1st Earl of Thanet b. est 1578 d. 1 Jul 1632
Frances Cecil was baptised on 28 Feb 1581 at St Martin's-in-the-Fields, the youngest daughter of Thomas Cecil, later 1st Earl of Exeter (cr. 1605), by his wife Dorothy Neville. She married Nicholas Tufton, later created the 1st Earl of Thanet (cr. 1628). His parents were John Tufton and Christian Browne.
Her parents: Thomas Cecil and Dorothy NevilleThomas Cecil (b. 1542) was the only child of William Cecil, Lord Burghley, Queen Elizabeth's famous Secretary of State (or chief adviser), by his first wife, Mary Cheke, daughter of Peter Cheke of Pirgo, co Essex and his wife Agnes. Mary died when Thomas was a little more than a year old. William Cecil then took a second wife in Mildred Cooke who was herself a learned scholar, being unusual for her day, in being able to read in Greek. They had three children together.
Thomas never knew his maternal grandfather Peter who had died before William Cecil and Mary Cheeke married. However, Agnes when she made her will in 1548 bequeathed to her grandson Thomas her new bed with the hangings, to be held in trust, until Thomas came to school at Cambridge.
Thomas Cecil, married, shortly after his education, to Dorothy Neville, perhaps as much as six years younger than he. She was the daughter and co-heiress of John Neville (d. 1577), 4th Baron Latimer, by his wife Lucy Somerset (d. 1582), daughter of Henry, 2nd Earl of Worcester.
In 1605, Thomas Cecil was raised to the peerage as 1st Earl of Exeter, and Dorothy could then take the style "Countess Exeter". She however was not to enjoy her title for long, dying 23 Mar 1608 in London. Thomas Cecil then took as his wife Frances Brydges, the daughter of William Brydges (d. 1602), 4th Baron Chandos of Sudeley by his wife Mary Hopton (d. 1624). Frances was the widow of Sir Thomas Smith, Master of Requests to King James.
By this union Thomas Cecil had a sole daughter Anne, who died as an infant on Sep 1621. He outlived that daughter a little over a year, dying 8 Feb 1623 in London.
Thomas Cecil by his first wife however, had a number of children who survived to have issue. The youngest of these was Frances Cecil who was born in 1581, and sometime before 1603 married Nicholas Tufton, later created the 1st Earl of Thanet (cr. 1629). His widow Frances Brydges lived until 1663.
His parents: John Tufton and Christian BrowneJohn Tufton's year of birth is not known, but he was certainly an adult by the time he was Sheriff of Kent in 1575. His father, also John Tufton, had died 15 Oct 1567 "aged 47", John the son must have been born sometime between 1537 and 1555.
John, the son, was married firstly to Olympia Blore, she was the heiress of her father Christoher Blore of Blore's Place. She and John had three daughters, co-heiresses of their mother: Anne, Elizabeth and Margaret. It is not clear that Elizabeth survived her mother, but if she did, she died shortly thereafter unmarried. The eldest co-heiress Anne married Francis Tresham of Rushton famously connected with the "Gunpowder Plot", he died in the Tower of London in 1603. The youngest co-heiress Margaret married Sir Thomas Caryll of Benton and Shipley, co Sussex, and their daughter Mary Caryll married Richard Molyneux, created Viscount Marlborough in Ireland.
Olympia Blore died sometime between 1563 and 1577, whereupon John Tufton, married a second time to Christian Browne, daughter and co-heiress of her father Sir Humphrey Browne, Chief Justice of the Common Pleas by his wife Anne Hussey of Sleaford.
John Tufton lived at Hothfield, co Kent where he was Sheriff in 1575, knighted in 1603 and finally created 1st Baronet in 1611. By his second wife Christian Browne, he had five sons and one daughter. His eldest son was Nicholas Tufton, who would later be created the 1st Earl of Thanet. Nicholas was baptised 19 Jan 1578 at Terling. The other children, for whom I don't have any exact baptismal or birth information were John, Richard, Cicely, William and Humphrey. The daughter Cicely would later become the Countess of Rutland, by marrying as her second husband, Francis Manners (1578-1632) the 6th Earl of Rutland. William Tufton would become the Governor of Barbados, where he died in 1650.
Nicholas Tufton and Frances CecilNicholas Tufton and Frances Cecil married sometime betwee 1595 and 1602. Their two eldest children were William who died in his father's lifetime and Elizabeth who married on 25 Nov 1619 to Edward Dering "of Pluckley", but inheriting the family estates at Surrenden in 1636. I do not know if William or if Elizabeth were the eldest child, but these two were almost certainly the two eldest. The next child was Frances, a daughter who died unmarried.
Then followed another daughter Dorothy Tufton who was perhaps baptised on 23 Mar 1606 at Hothfield, co Kent, which information is found on a LDS Patron Sheet submit to the I.G.I. Regardless of that, it is certain that she married Ralph Ashton of Whalley, co Leic, Knt and Bnt. Perhaps they married on 17 Apr 1630 at Hothfield, but again this information is only found on an LDS Patron Sheet. Ralph was the eldest of ten sons of his father, another Ralph. This family of Ashton of Whalley had the perhaps unique distinction that although having ten sons, all ten died without issue, whereupon the baronetcy that had been placed on the senior Ralph, expired.
The next child of Nicholas and Frances' was John Tufton, born 15 Dec 1608. Since his elder brother William had died in the lifetime of their father Nicholas, John even though second son, was his father's heir when Nicholas died in 1631 or 1632 (sources differ) at Sapcote, co Leic. Before that time however, John had married to Margaret Sackville (1614-1676) on 21 Apr 1629. This was quite a fortuitous match for John, as Margaret was daughter and co-heiress of her father Richard Sackville, 3rd Earl of Dorset by his wife Anne Clifford. Through this Clifford connection, Margaret would later become, at least briefly, Baroness Clifford suo jure. John Tufton and Margaret Sackville, must have had a remarkable well-suited marriage, as they produced twelve children over a period of twenty-three years. John Tufton died at Thanet House, London on 6 May 1664, while his wife Margaret outlived him, dying 14 Aug 1676.
The next child of Nicholas and Frances' was Nicholas Tufton who died as an infant.
He was followed by Mary Tufton, their fourth daughter, who married Edward Bishopp of Parham, co Sussex. Edward was knighted in 1625, became the 2nd Baronet when his own father died. But I'm not yet sure, when or where exactly Edward and Mary married. They had at least two children, and their progeny existed at least a hundred years later. I had not traced it beyond that.
Then followed Anne Tufton and Alice Tufton who died as infants.
The seventh daughter was Christian Tufton, who married William Milward of Chilcote, co Derby; esquire.
The eighth daughter was Diana Tufton who married Robert Curzon of Water-Pyrie, co Oxon; knight.
The youngest son, and no doubt, youngest child was Cecil Tufton. He was born between 1618 and 1620 and died 19 Jun 1682 at Lincoln's Inn Fields, being buried at Rainham on 21 Jun 1682 "aged 63". Cecil married on 31 May 1660 at St Peter, Paul's Wharf, to Mary Lloyd. They had at least one child: Charles Tufton of Twickenham.