score:4
Unless someone can find a "smoking gun" such as a diary, we'll never know for sure. But the "indications" appear to be no, for several reasons.
Marie had a difficult childbirth with her last child. She was the one that said no to further marital relations, which amplified any tendencies that Louis XV might have had toward infidelity. It's unlikely that a queen consort would refuse her husband, then sleep with other men.
She was some seven years older than Louis XV, not the kind of woman most men would want for a mistress.
She was a "down to earth" woman from a "poor" family (for a noblewoman), not popular among other nobles.
She was a good-hearted woman who was basically in love with Louis XV, at least initially (which is on the "rare" side in those days).