Underwood in Somersetshire

My Underwood family start back in Evercreech in Somerset in 1695 with Jeffrey Underwood son of Jeffrie. He married Elizabeth "Betty" Hunt in Evercreech in 1720. This couple had to my knowledge two children: Joseph born 1731 and Elizabeth born 1744 in Evercreech. I am guessing that there must be more children born to this couple given the distance in ages and from their marriage date but I have yet to find them.