There are possible earlier Baptisms in Burston (near Diss) for John/Ann Gray
MARY ANN, 16 Oct 1814
ROBERT, 25 Aug 1816
DINAH, 1 Nov 1818
PINSBY, 14 May 1820 (female) actual record is EMILY, also as Emily 16 May 1820
Mary Ann has Mother as Ann Lockwood Gray and another record, Ann LOCKWOOD
Source Familysearch.Org
What made me look back further is that in 1851 John/Ann are visiting in Parham, Suffolk;
Henry Clarke, 45
Louisa Clarke, 35
Eliza Gooch, 42
Jane Patnoster, 30
ROBERT Gray, 35, Servant,Unm, Farm Steward, born Scole, Norfolk****
William Buckingham, 26
Henry Buckingham, 30
JOHN Gray, 57, Visitor, Mar, Ag Lab, born Scole, Norfolk****
ANN Gray, 55, Visitor, Mar, born Scole****
So visiting their Son?