They would be born prior to censuses, probably in the 1750s and 60s. There is info from the Horfield parish church online that one of their daughters
Isabella is buried in the churchyard, died aged 3 yrs 2mths in 1763.
John
Shadwell snr died in Brussels in 1777 and was
Lord of the manor of Horfield. His son John took over, followed by another son Richard. Isabella
Shadwell nee Mitchell died in
Bristol in 1815 aged 85.
So that is 3 of their children I know of. Just want to confirm Thomas Mitchell
Shadwell is another one.