I can't seem to find a Marie Louise Veronneau dit Denis, but I do find a Marie-Claire Veronneau who would fit in that time frame.
Her father was Francois Veronneau (b. 1738) m. 1760 to Clotide Gareau (b. 1743).They had quite a number of children including my ancestor Francois Veronneau dit Denis who was born 1760.He was married in 1792 so it would make sense that he may have had a sister named Marie Louise married a short time later.
Francois Veronneau (b. 1738) is the son of Francois Veronneau (b. 1707) and Catherine Robin (b. 1708). Francois (b 1707) is the son of Denis Veronneau (b. 1641 or 1635) m. to Catherine Guertin (b.1664)
If you think this is the right tree, feel free to email me for more information.