As I'm going through the family tree, I'm frequently surprised by the intricate circumstances of marital relationships I encounter. We're continually fed this idea that live was MUCH simpler in days gone by, and that the norm was that one man married one woman for life, in comparison to the norms of today where people marry, divorce, raise families outside of marriage, etc.
But while cultural norms change over time, the idea that we've moved from some simplistic "ideal" to a more-complicated set of domestic arrangements is somewhat misleading. In reality - as I continue to discover - sometimes circumstances could be just as abnormal then as now. I suppose it's yet another example of the conditions in early Québec - the comparative isolation of communities, combined with what probably was a pragmatic response to circumstances of availability, e.g., the programs set up by France to increase the population of women in Québec in the mid-1600s: the "Filles à Marier" and the "Filles du Roi".
The harsh conditions of life and care meant that many people died young: men in the course of work, women from complications of child birth, not to mention disease, and also through violence from attacks by the native population (as well as battles with the British). Providing continued care for families - many with young children meant re-marriages were extremely common; it was an early-on revelation to me that the time frame from the death of a spouse to a re-marriage seemed EXTREMELY short - frequently only a few months. But while all of this happened, some of the specific re-organizing of families (and their respective family trees) can sometimes appear to be rather "un-conventional".
The most well-known trope is cousin marriages, and consanguinity does appear all over the population, mostly among second cousins (or more distant relations), though first-cousin marriage definitely take place (though it's not quite AS frequent as I expected). What's more common than I had expected are situations where siblings marry people who are also siblings (i.e., all the in-laws are shared). Where it gets strange (at least to me) is where there are marriages involving someone with an in-law of one of their children: for example, a daughter (say Marie) in family X marrying a son (say François) in family Y. Marie's mother dies (or has died) and her father re-marries a woman who is either the François' mother (making Marie and François step-siblings à la Greg and Marsha Brady), or even weirder/creepier François' sister (making Jan both Greg's sister-in-law AND step-mother)!
Today I came across another strange situation, that of 7th great-grandfather Noël Barabé and his relations with the Tousignant family (Pierre Tousignant dit LaPointe and Marie-Madeleine Philippe).
He first marries eldest daughter Marie-Marguerite in 1687. They have a son Jean-Baptiste in c. 1689. They might also have a daughter, Marie-Renée out of wedlock (we know that Noël is her father, but her mother is not mentioned). There's no other mention of other children, but Marguerite dies before 1697 because Noël marries Marguerite's sister Michelle (who is my 7th great grandmother) around 1697.
I enjoy trying to sort out what to call the familial relationships: Noël and Michelle have 10 children who are Jean-Baptiste's first cousins AND step-siblings. He grows up with "aunt Michelle" who becomes "step mom Michelle". I have to wonder how families adjusted when the labels of relationships change - did the adopt the new nomenclature, or stay with the old?
(I'm also curious as to what Marie-Renée's life was like - there's no information about her life other than her birth date. Illegitimacy was more commonplace than the record (or the church) would suggest: genome analysis of the Québec population reveals that the church records on parentage could be off as much as 10%!)
 Marie-Madeleine Philippe was a Fille du Roi.