The adjective contentus (satisfied, content) can be modified with ablative.
For example, viro contentus means "satisfied with a/the man".
In your case the attribute has two words: unus vir (uno viro in ablative).
Therefore I would translate like this:
Uxor, quae bona est, uno viro est contenta.
A wife, who is good, is satisfied with one man.
I added ...
This doesn't quite make the 1900 cutoff, but:
Arcadius Avellanus, born Mogyoróssy Arkád in 1851 Hungary, is said to have been the last native speaker of Latin. In 1878 he emigrated to the US, where he became a Latin teacher, advocating (evidently with not much success) living Latin.
I looked through his translation, published in 1918, of Guy de Maupassant'...
Certainly the concept of subordination existed in antiquity; the Greek grammarians used ὑποβάλλω or ὑποτάττω to mean "to subordinate syntactically", and derived from this the term ὑποτακτικόν "subjunctive" (because the subjunctive mostly occurs in subordinate clauses). The Latin terms subordinare, subiungere, subiunctivum are calques of these. They also had ...
articulus ... Hence, a short clause, Dig. 36, 1, 27; also, a single word, ib. 35, 1, 4: articulus Est praesentis temporis demonstrationem continet, ib. 34, 2, 35: [Lewis and Short(TUFTS)]
membrum II B 3 Of speech, a member or clause of a sentence:
quae Graeci κόμματα et κῶλα nominant, nos recte incisa et membra
dicimus, Cic. Or. 62, 211; cf. Auct....
I suspect one of the things that's throwing you off is the word order: it would have been much easier if the sentence had been
uxor quae bona est contenta est ūnō uirō.
However, that order feels sort of strange. The thing to remember is that Latin word order is very flexible (though not infinitely flexible), and often words that appear right next to each ...