1881 shows a widowed Jane E. McKay, 44 b Southampton, in Hackney with 14 yr old son Fred J. McKay b St Pancras. She's a mantle maker which is close to Emma's 1871 occupation of dressmaker. RG11/297/11/16
So perhaps, if this is the right family, we should be looking for a marriage of a Jane Emma [Bath]?
Anna