It might be a misunderstanding. In many languages, there is one commonly used word that translates (out of context) to "wife", "unmarried partner" and "woman" at the same time.
That's the word the Bible uses for Eve. It means all three words, as you've mentioned. Being biblical, this form of speech is not uncommon in many European and Middle Eastern cultures and languages.
(edited to match parent) Her mother was Helena Jens, and she was already married to another man at the period this article talks about. Descartes was also back in France while she was still in the Netherlands.
Although Descartes did vivisect animals for research purposes, I think it's safe to say that this particular account is an invention.
That's the word the Bible uses for Eve. It means all three words, as you've mentioned. Being biblical, this form of speech is not uncommon in many European and Middle Eastern cultures and languages.