Terince Fitzsimons, Drumderg Twp, County Cavan, 1821 Census

I believe that my ggggf is a Terince Fitzsimons, who is listed in the 1821 Census as living in Drumderg Townhip, County Cavan, with his wife Anne, and three or four children.  Terince's birthday is calculated at 1771, Anne's as 1775.

So, am seeking further information on TERINCE and ANNE FITZSIMONS of Drumderg, County Cavan, circa 1770 - 1850 ish,

Census records would indicate that Terince had a sister Catherine who was a schoolmaster in the area, and a second (older) sister, Margaret, who lived with Catherine,

Drumderg is located between Balliejamesduff and Virginia.