Heather, I am sorry to say but your sources are all WRONG! Pierre du Lignon de la Mirande was the eldest son of Theodore du Lignon and Martha Pasquet. He was born 20 Jan 1655/56 in La Rochefoucauld, Angoumois, France. He married Marguerite De Gerlais (Wayne I would love to hear from you about this family)27 July 1703 in Louiseville, Quebec. Thirteen children were born to this couple.
Jean du Lignon was the second son of Theodore and Martha. He was born 16 June 1657 in the same city mentioned above. He came to Quebec before Pierre, and that may be where all the misconceptions about him being the father of Pierre comes from. He did marry Marthe Testard 9 Oct 1684 in Montreal, Quebec. They did have a son named Jean born 14 June 1686 in Montreal. As far as we know Jean's line daughtered out and there are no descendants. I have found one reference of Jean du Lignon accompaning de La Salle on his mission of discovery in 1682.
Several cousins have formed a Pierre du Lignon de Lamirande Society. We are trying to gather the correct information on the family and hope to correct all of the false data associated with Pierre and Jean. If any of you care to join us, please send me an E-mail message and I will have you entered onto our membership rolls. At this time there are no dues and we are publishing a newsletter. Our first newsletter was sent out last November. The second newsletter is due out sometime this month.