Re: holehouse family
If there is no father's name and occupation on the birth certificate it simply means that Dorothy was illegitimate. Her father may have been Mr Jones but it would appear that her mother wasn't married at the time of Dorothy's birth.
Dorothy may have been led to believe that she was a Jones if her mother married Mr Jones when Dorothy was very small.
However, Dorothy must have had a passport in order to get to Canada and it would be interesting to know what name she used!
Hope this helps.