Hi Shari
Been looking through the baptisms for children of William & Ann
A/S = All Saints
S/C = St Clements
Whilst I have the same names as you - I have different dates
A/S - William, 2nd Feb 1766
A/S - Sarah, 14th Jul, 1762
A/S - Ann, 8th Feb 1764
Possible children of William & Sarah taken from the Baptism Register are:
A/S - Sarah, 13th Jan 1788
S/C - Thomas, 20th Nov 1792
S/C - Joseph, 1st Mar 1795
S/C - James, 13th Mar 1796
S/C - Robert, 28th Apr, 1799
A/S - Ann, 5th Apr 1801
S/C - George, 29th Jun 1804
A/S - Thomas, 8th Oct 1806
S/C - Barbara, 17th Jul 1807
Looking at later baptisms, it would appear that Thomas, Joseph, James and Robert all married and produced children.
Hope the above helps you a bit
Chris in 1066Land