I asked her how her youngest son was doing
Why did you ask her about her youngest son?
I was just wondering. Turns out he's a bad loser just like his dad.
Describing both him and her son as losers is rude and inappropriate behavior. If you think of them and their family so negatively, it will show in your behavior and turn into a self-fulfilling prophecy.
No, I'm going to use this to show that their son does need therapy and that it's actually their wife that has problems.
Taking an interest in other people's families should bring out your concern, not confrontational demeanor. If their family is having problems, either assist them and don't spread rumors.