I wonder if it was less that and more she knew when bereavement calls were going around and let her husband know about them so he could get the jump on Strowger.
While that is possible, remember that in those days all calls were operator connected. In the case of a bereavement, the caller would most likely ask "to be connected to the undertaker" - and if there was more than one, then it would be for the operator to choose. Obviously, if her husband is an undertaker, the operator is going to put such calls through to him.
I'd say impossible to determine the reality now - but regardless of reality regarding the claims, it prompted development of what has to be considered the cornerstone of telephony for many decades.
As a sidenote, to watch "Strowger gear" in operation, it's an engineering marvel - mechanically counting pulses, searching for a free circuit, just amazing that it ever worked at all, let alone reliably. It is said that an experienced exchange engineer could tell if the exchange was working properly (as a whole) just by the noise it made - and a room full of Strowger gear in full flow was certainly far from silent. There's a reason telephone engineers like Tommy Flowers were involved in the Bletchly Park operations. Icon for all of them, they deserved a good round.