Actually, that particular photograph (the girl holding the Inglis pistol with buttstock attached) wasn't taken at the Inglis factory, but at Small Arms Ltd. site (i.e. Long Branch) which is where the wooden buttstock/holsters were produced, since Inglis lacked any woodworking facilities .....
The full caption on the photo is "WAR EQUIPMENT FOR CHINA - SMALL ARMS LTD. LONG BRANCH ONT. - APRIL 1944. Madeline Solotwinski checks wooden holster which also serves as emergency butt on Chinese pistol, converting it into a sub-machine gun. This butt was specially designed for pistols shipped to China." (If you look closely, you'll see that it is a "try pistol" (for checking the fit and lockup of the buttstocks - it is basically just a frame and slide - there is no barrel installed.)
That and the other WWII photographs on the above linked site - and MANY other very interesting oness - are available for viewing and download on the Library & Archives Canada website, specifically in the resource in the "Art and Photography" database section which is titled: "National Film Board of Canada: War Records- Manufacturing (WRM) Series".
It's definitely worth a look .... and being bookmarked!
A hint for browsing: when you search the database, be sure to click the "Descriptions with a digitized image" box - otherwise you'll get a listing of every image in the collection, not just the ones available for viewing online.
Also, when you reach the page displaying an individual photo with the information relating to it, be sure to click on the small photo displayed, to see a larger version .......
As examples, and to demonstrate that it certainly wasn't just Inglis employing women (including many young, attractive ones at that) here are two images which resulted from my searching the term "Dominion Arsenals" -
"GIRLS AT DOMINION ARSENALS PLANT, QUEBEC - August 1942. Laurette Maurice, 19, who has been working in the Arsenal for two and a half years, is a checker, drawing 40 cents an hour. Engaged to a co-worker, she lives in Quebec with her family: father, mother and twelve other children. One brother is in the Army."
"GIRLS AT DOMINION ARSENALS PLANT, QUEBEC - August, 1942. A new shift arrives. The working day is divided into three shifts: 7 a.m. to 3 p.m.; 3 p.m. to 11 p.m.; and 11 p.m. to 7 a.m., girls changing shifts each week. Train ride is free from Quebec City to Arsenal in the outskirts of town."