I don't know if this helps, but I have a John Lister in my tree, a couple of generations earlier than your Margaret and George.
He got married in St Bride Fleet Street in 1763, and though they lived on Fetter Lane (which is around the corner from St Andrew Holborn) all but one of their children were baptised in St James Clerkenwell.
He was a carpenter / cabinet maker and had only one surviving son, also called John (b1765).
There are chances that Margaret and Martin Lister are related to them...