The children were (dates are baptisms, not births):
Samuel 17.11.1758
Elizabeth 28.9.1760
John 1.5.1762
Tabitha 15.4.1764
Robert 9.2.1766
Jeremiah 26.6.1768 (and buried on 15.1.1769, poor soul)
Jeremiah 18.10.1769
Sarah 17.5.1772
Susannah 17.5.1772
The other John Brocks:
John Brock m. to Elizabeth nee Reeve, then Nunn, then widowed. Had a daugher Mary, b. 25.5.1798
John Brock, widower m. Susan Morrell, widow, 29.9.1794 (surely not your John marrying 6 months after Elizabeth's death?!
John Brock, widower, m. Mary Bell 22.6.1802
best wishes
meles