I think that this is Isabella FELL who md Charles Watterson 15 May 1858 Rushen
Their daughter Margaret md Samuel Keggen/in Rushen 29 OCT 1881

I thought this might be the FELL connection.

1881 Rushen Census
, 5, 6, 32, WATTERSON, Isabella, High Street, Head, Widow, 58, Housewife, P.StMary
, 5, 6, 32, MOORE, Eliza, High Street, Daughter, Married, 22, Dressmaker, P.StMary

Elizabeth WATTERSON ch 22 MAY 1859 Kirk Rushen
No father listed
Mother Isabella WATTERSON

DJD