John married Abiah Kornic. Abiah died in Boston, MA on 3 Sep 1715.
Children of John and Abiah (Kornic) Flagg:
i. Abiel Flegg;
ii. John Flegg, b. 20 Oct 1699;
iii. Hannah Flegg, b. Apr 1701, d. 12 Dec 1702;
iv. Eleazer Flegg, b. 12 Feb 1702;
v. Gershom Flegg, b. 20 Apr 1705;
vi. Ebenezer Flegg, b. 9 Mar 1707, d. 27 Aug 1708;
vii. Hannah Flegg, b. 14 Oct 1708;
viii. Ebenezer Flegg, b. 27 Oct 1710; and
ix. Thomas Flegg, b. 8 Jul 1712, d. Sep 1713.