Hi, Don't know this "middle-name" Kilvert, but... Some of the male descendents of my grandmother, Elizabeth KILVERT (of the Wernlass Kilverts), have used the middle name of“Kilvert”. The practice began with my uncle, Aubrey Kilvert Thomas.
Descendants of Elizabeth KILVERT (Wernlass Kilverts)
1. Elizabeth KILVERT (b.1869-England d.Aft 1962) immigrated to US as "Ellen Kilvert" July 1, 1895 (see Ellis Island Records) sp: Thomas THOMAS (b.1866-Llanllyfni,Caernarvon,Wales |m.July 4, 1895-Neenah,Wisconsin,USA d.1919-Cheboygone,Michigan,USA) |-2. Aubrey Kilvert THOMAS Sr (b.18 Sep 1897-Neenah,Wisconsin,USA |d.Abt 1955-Detroit,Michigan,USA) | sp: Gladys(m.Abt 1917 d.Abt 1950) ||-3. LivingDaughter THOMAS married, 5 children and many grandchildren ||-3. LivingSon THOMASmarried, 4 children and many grandchildren | sp: Isabelle(married.Abt 1952 d.unknown) no issue from marriage +-2. Dorothy or Gwendolyn THOMAS (b.17 Oct 1910-USA d.12 Dec 1993-Damariscotta,Maine,USA) sp: Leonard Fellows DEAN (b.24 Dec 1909-Three Rivers,Michigan,USA |m.Abt 1931 d.02 Nov 1999-Damariscotta,Maine,USA) |-3. Nancy Ann DEAN (b.17 Dec 1934-Ann Arbor,Michigan,USA |d.03 Dec 1999-Manchester,Connecticut,USA) never married - no issue +-3. Elizabeth Jane Dean VANASSE (b.17 May 1945-New Orleans,Louisiana,USA) "Me" - married with living, married daughter