Tammy, my husband is descended from Ann Daux. I am a RANK AMATEUR, but wanted to contribute the (conflicting) information I have been able to find about this family. I don't have documentation either, but found most of this at ancestry.com, so take it for what it's worth ...
I have William Guilliame Witt (b. 1661, '75 or '80 in Pays D'Anis, La Rochelle, Aunis, France; d. 6/13/1754 in Roseland, VA-now Nelson Co but it has changed jurisdictions several times over the years) married Elizabeth Mildred Daux (b. 1684 in France; d. 1741 in Albemarle Co, VA) in 1698, 1700 or 1708 in either France or Virginia. No info on Elizabeth's parents.
William's father was John Whitt (b. ~1645 in Ross, Herefordshire, England; d. 1715 in Charles City Co, VA), who married Anne Daux (b. ~1650 in Charles City Co, VA) in 1669 in Albemarle Co, VA.
John's father was Robert Whytt of Ireland, who also married Ann Daux. I don't know if it's the same or a different one.
In the other direction, I have William and Elizabeth's son John (b. 1710 in Albemarle Co, VA; d. 3/9/1782 in Amherst Co, VA) marrying Lucy Elizabeth Littlebury (b. 1720 in Goochland, VA; d. after 1782). My husband's line follows their son David (b. ~1750 in Pittsylvania Co, VA; d. 8/28/1818 in Nelson Co, VA) who married Sally Abney (no info).
Many of those on ancestry.com have extensive sibling lists, so if any of this fits in with what you have, I'd suggest you check there. If you can add to or correct any of what I have, I'd really appreciate it!