Big Rachel

Big Rachel was originally from Ireland, but lived in Partick, Glasgow.
She worked as a labourer in the shipyards and as a forewoman navvy at a Brickworks and as a farm worker.
She was 6 feet 4 inches tall and weighed around 17 stone.
She was sworn in as a special police constable during the Partick Riots in August 1875.
This was definitely non-traditional work for a woman in those times.
Why do you think Rachel managed to make it in a non traditional job?