I also am a descendant of Elizabeth Mildred Daux's grandson Davis Wittand wife Sally Abney. She was most probably the daughter of Dannett Abney. There appears to be a question as to which of the Abney's Dannett son was her father as it was a common family name.
They appear to have been well researched back to England, with a Lord Mayor of London, an ancestor. I haven't gone much further back than that, though others have.