Yes Chiff, Mireille first won a competition similar to 'Opportunity Knocks' several weeks on the trott, and singing Piaf's songs. Very soon after that she was given songs of her own to sing and made it to the top in no time.
I believe she is still goind strong now aged 69, and is famous the world over. The French TV showed her performing in Moscow as a solo with the Red Army chorus - Quite something!