still not getting it

Question

The first sentence, "il faut vraiment que l'on discute de ta mère" is the contraction l'on for "le" or "la" ? I still don't get why it is even needed. Would it not work to say, "...qu'on disute de ta mère" which then maps to English as "that we discuss about your mother".
I'm guessing that it's a direct object pronoun, but then why isn't "de ta mére" the object of the sentence?

Accepted Answer

Craig, the “ l’ “ here is for euphony. It has no meaning or grammatical role in this context. It is not an object or pronoun, as it only represents an optional pronunciation. 
It is still used in everyday speech, but not frequently. It is heard more commonly on radio and television news, discussion, debates etc, and in more formal speech generally. 
Yes, he could have just said ‘ qu’on…’, and this is what you will mostly hear in everyday speech nowadays.
See link for explanation: 
 https://www.lawlessfrench.com/grammar/on-vs-lon/

Answer

Bonjour Craig,discuter⇒ vtr(débattre)discuss⇒ vtr  talk about vi + prepI have pasted the above from "word reference" -- To express "talk about" is discuter plus preposition in this case "de".So the "de" in "de ta mére" is the preposition before the object "ta mére" "L'on" expresses "We must discuss it" -- it(l')being the matter to be discussed.Hope this helps.Bonne journéeJim

Answer

Merci Jim et Maarten !
I am not sure which of your answers is "more" correct, but they both seem to make sense. I had not seen "euphony" discussed much in my progress lessons, at least not by that term, and the on-vs-lon article is very helpful.