I have searched for the death of her first husband Isaac Banks but am unable to find it, please help!!
He was last seen on the 1871 census, by the 1881 his wife (Sarah) Alice Banks is living in Wilfer Street as the wife of a seaman. She has with her sons Thomas and George.
Piece 3708/F106/P4
Son Nathaniel is born in 1882 and christened in Fairfield.
By 1891 she is still living in Wilfer Street in another house but with a man called Charles Briscoe, the son Nathaniel Banks is shown as N. Briscoe

There is no sign of Thomas and George in 1891 with them, as you may remember Thomas (Henry) is possibly the one in Orford Barracks but I can't be sure and George may be a 15 year old porter in Bathwick, Somerset, maybe they both hated their stepfather and had to get away??
Anyway when Nathaniel gets married in 1909 to Mary Platt he calls himself Nathaniel Briscoe Banks but strangely his father is shown as Charles Briscoe Banks.

Alice marries as Sarah Alice Briscoe for a 3rd time to Nathaniel Forshaw Platt in 1906 possibly related to Mary Platt above but I'm still working on this.