Many thanks to everyone for their comments, especially Jaywit & Toni
To answer some of the questions (as best I can
):
The baptism entry for Henry (1824) unfortunately gave no details of the father.
Henry (Frances’s son) was an apprentice tailor in Norwell (near Southwell) in 1841. He was the only of the grandchildren of Frances’s father who was given a special mention in his will – so he probably took after his grandfather.
I could find no other children of Frances/Frances & Charles.
I have looked for bastardy bonds, etc. by emailing the Nottingham archives. They were very kind and did a check under the surnames Johnson, Steward and Frecknall for me, without finding anything. That makes me think that Charles (the father?) stuck around to support the child – and therefore there was no need to go to the parish for support. I will try to make another search of those records in case something was missed.
Where/how would I check poor relief/tithe/land tax records? At Nottingham? I am on holiday in the UK at the moment and am hoping to get to the Nottingham archives in a week or two.
I have tried all the routes for finding a burial of Charles – none that fit in the Upton or Southwell registers. Also I’ve tried looking for a Steward-Johnson marriage with no success. The surname Steward (that spelling) seems relatively uncommon in Notts at the time (at least compared to Johnson).