there appears to be only one McGain family in the 1881-1900 era based in 1881 in Ballasalla but then moving to Port Erin (eg use search on manxnotebook - one member appears to have died in WW1 and is on the Manx RoH) - in 1881 the head of family is shown as Isabella indicated as married (not widowed) but no husband - there is room in the family for a dau of the correct age but no obvious match - tho Isabella born Ireland the children are all born Malew (which includes part of Foxdale)