Just to stop others repeating work, the proposed Martha Fleet/Ellis is in censuses:
in 1841
Henry and Martha Ellis, both aged 50, he is a wheelwright, living in Row 29 in Great Yarmouth with William Fleet, apprentice basket maker, all local.
In 1851 Martha Ellis is widowed living on her own.
In 1861 Martha has Elizabeth living with her as niece age 24.
In 1871 Martha is grandmother and Elizabeth is age 35, living at 19, Row 120.
Then on the marriage in 1872 the bride and groom are both from Row 121.
Living on Row 121 in 1871, at dwelling 12 is Martha Fleet, 23, Fisherman's wife, Martha Fleet,5, James Fleet, 10 months, and William Wells, 26, boarder, fisherman.
Think Martha is wife of this possible marriage:
Marriages December quarter 1867
James Fleet Yarmouth
Martha Wells Yarmouth
and Martha born before marriage as Martha Harriett Fleet Wells in 1866
Added:
James Fleet's Father is also a James Fleet (according to marriage information), and James junior born about 1846, so possible cousins to other Fleets, but not brother. James junior at sea in 1871, and also naval reserve.
Added: Cannot see a birth for him, or in a census before his marriage, so possibly his parents had a late marriage.