There is a tree on Family Search that gives:-
-Adam Turfery, batpised March 16th 1787, Leafield, Oxfordshire, the son of Thomas Turfery and Rebecca Bosely. It notes a brother, Thomas b. 1785 in Leafield, Oxfordshire.
Also in the tree is the marriage to Rebecca Bosely, August 1st 1770, in Shipton-Under-Wychwood.
Like you, I can't find any mentions of children prior to 1785 which seems weird to me.
JackB