Thank you for the insight. It was explained by a contributor at the FR>EN forum at dict.cc that ma colonelle would be 19th-century French for a colonel's wife, not for a female military officer of that rank, which at the time would have been unheard of.
A similar situation occurs in 19th Century DE, wherein Medizinalräthin refers to a medical counselor's wife, not a female medical counselor.
Thanks again!