Keeping in mind that I've not seen the article in the latest edition of The Virginia Genealogist, I won't try to duplicate the documentation offered to prove the link between Frances Baldwin and Francis Mackworth (d. 1557) of Empingham. I will, instead, give a brief account of why I believe there is also a descent from William I of Scotland.
On pages 243-245, VCH Rutland covers the ownership of the Manor of Empingham as it passed through marriage and inheritance from the de Normanville family to the de Basyngs/Basings family to the Mackworth family. On pages 244-245, Francis Mackworth is shown to be the son of George Mackworth (d. 1535) of Empingham (by Anne Sherard according to my own research), and the grandson of John Mackworth (d. bef. 1487), by Beatrice (whose surname is unknown, as far as I've been able to determine). John Mackworth was, in turn, the son of Henry Mackworth (d. 1487), possibly by Agnes de Sallowe (although the Mackworth lineage in Blore's history of Rutland shows Henry's wife as Ellen with no surname given). Henry Mackworth was the son of Thomas Mackworth (d. 1439) of Mackworth (in Derbyshire) and his wife Alice de Basynges/Basings (d. sometime after 1457 but before 1484) sister and eventual heir of Sir John de Basynges/Basings (ca. 1376-1445) of Empingham.
In Feb. 1998, S.J. Payling's article, "Murder, Motive and Punishment in Fifteenth-Century England: Two Gentry Case-studies" was published in the English Historical Review. I found my copy of this article online (through Google as it happens) so I don't have the vol. no. and correct pagination to provide, but can hunt it down if necessary. Anyway, one of the cases in question involves Alice (de Basynges) Mackworth and her son Henry and their eventual succession (through the murder of Sir John de Basynges' illegitimate son) to all the de Basynges properties. Payling notes that Sir John de Basynges and William, Lord Zouche of Harringworth (fl. 1439) were cousins and that Sir John's mother was, in fact, the great-aunt of the Lord Zouche in question. Turning to CP (vol. 12, pt. 2, page 942, note G) I found that Elizabeth Basing is mentioned as the daughter (along with Majory Willoughby) of Elizabeth de Ros (d. bef. 8 July 1382), widow of William, 2nd Lord Zouche of Harringwo!
rth (d. 23 April 1382). VCH Rutland (page 244) indicates that Alice Mackworth was age 50 or more at the time of her brother's death in 1445. The same source (and page) also shows that their father, another Sir John de Basynges, lived from 1341 to 1384 and that his three children were Thomas (died childless in 1400), Sir John (ca. 1376-1445) and Alice (d. sometime between 1457 and 1484).
While Payling doesn't specifically state that Alice Mackworth and Sir John de Basynges were full siblings, nothing I've found so far (including both the text and lineage in Blore and the VCH Rutland) indicates that they were anything but the children of Sir John de Basynges (ca. 1341-1384) and his sole wife Elizabeth. Assuming then that they were indeed the children of the same mother, it's a simple matter to trace Alice (de Basynges) Mackworth's descent from William I of Scotland through her mother Elizabeth de Ros on page 424 of Roberts' The Royal Descents of 600 Immigrants. The line is as follows: William I (d. 1214) à Isabel of Scotland m. Robert de Ros à Sir William de Ros m. Lucy (Roberts says Lucy St. John, but I think this was discussed and dismissed on Gen-Medieval a while back) à Sir Robert de Ros m. Isabel d'Aubigny à William de Ros, 1rst Lord Ros of Helmsley m. Maud Vaux à William de Ros, 2nd Lord Ros of Helmsley m. Margery de Badlesmere à Elizabeth de Ros m. !
William la Zouche, 2nd Lord Zouche of Haryngworth.
It's rather late, as I'm typing this, so I hope you'll forgive me if I've rambled a bit.
Jeff Duvall