Hi
1841 census (on freecen)
Census taken Edinburgh Midlothian 
RIGGS   George   age  27   Shoe Maker   born Midlothian         
    RIGGS   Jane   age  25     born  Midlothian         
    RIGGS   Violet  age  7     born  Midlothian         
    RIGGS   William age   5   born  Midlothian         
    RIGGS   George age   2   born    Midlothian         
    RIGGS   Nicol     age   1month  born Midlothian  
By 1861 census Violet was living in Rutherglen age 25 born St Cuthberts
Edinburgh. no other family with her.
Also in 1861 index and taken Rutherglen
Daniel McGill age 60 born Ireland
Patrick age 31 born Ireland
Bernard age 26 born Ireland
What was her second husband's name? and I'll try to locate them 
1881 census
Liz
There was a Hugh McGill born 30th april 1861, Rutherglen to Bernard McGill and Violet 
Riggs
In 1881 census there is a Hugh McGill born 1861 Glasgow, living in Perth.
Hugh Mc Gill age 20 born Glasgow
occupation plumber
Living as a Lodger in Main St Callander, Perth