Plautus - if marie A did so, it was a commonplace practice in France of the time (and indeed until quite recently). Descriptions of the Palace of Versaille often include its complete absence of toilets, and even the gentry of the time simply did it where they could. Voluminous skirts on women made this a surprisingly modest action.
As for the original question, involuntary bowel or bladder movements before execution and after death would happen and were probably again simply absorbed by the clothing of the victim. people at that time bserved the same when slaughtering food animals and would not find it especially worth comment - not soiling oneself in the circumstances would be much more comment-worthy.