Youngest of four daughters in the Charles family, Marie-France's father was manager of a refrigeration warehouse and canning factory.

Her mother received the Croix de Guerre with palms, having been imprisoned by the Germans, and her two sisters were pillars of the resistance until the end of the war.

When the Stirbois couple joined the National Front in 1977, five years after its establishment, each embraced militant political activism.

Marie-France focused on local politics and represented the National Front in Dreux, first as a city councillor, then at elections in March 1989.

In March 1992 she was elected conseillère générale ((in French) "General Counsel") and then in June 1994, Member of the European Parliament and regional advisor.

Marie-France was twice sanctioned by National Front institutions and suspended from her duties in the party's political bureau.