"CBNRC’s (CSE’s) second headquarters was in a former convent that had been used as a military hospital during the Second World War.
The building was built by the Sisters of Charity of Ottawa (the Grey Nuns) in 1915 and served as their novitiate until 1941, when it was converted for use as the Rideau Military Hospital."
Possibly the Nuns took in unwed mothers?? http://www.soeursdelachariteottawa.com/English/home-english....http://www.soeursdelachariteottawa.com/English/history/archi...
Have you tried a search on the Drouin records?
Ontario, Canada, Catholic Church Records (Drouin Collection), 1747-1967http://search.ancestry.ca/search/db.aspx?dbid=1109
(Ottawa may be included in the Quebec records).
Quebec, Vital and Church Records (Drouin Collection), 1621-1967 http://search.ancestry.ca/search/db.aspx?dbid=1091
I think your query would get more answers if you posted to Canada > Ontario > Carleton.....there are more people there familiar with Ottawa.