Mary Ellen was mentioned in the 10 May 1840 will of her grandmother, Sarah Dix, proved 17 November 1840, as her granddaughter Roy. [Essex County, Virginia, Will Book 24, pages 541–542.]

In a chancery court case from 1840–1841, Telemachus B. Littlepage and Willy Ann his wife who was Willy Ann Dix, daughter of Thomas E. Dix deceased; James C. Roy and Mary E. his wife who was Mary E. Dix, daughter of Thomas E. Dix, deceased, stated that Thos. E. Dix, dead for many years, was the only child of Capt. Thomas Dix. Thomas E. Dix left a widow Sarah. Thomas E. Dix left a daughter Sarah, now deceased, who married a Mill and had a daughter Lucy Ann Mill, now an infant. Case from 1840–1841, Littlepage vs. Mill. [Essex County, Virginia, Box Chancery 39, Item 39-O-22.]