I 45m and my wife 42, recently had a disagreement with my in laws. I'm still struggling to process and don't want to involve extended family members, or friends as I don't want them to get involved or feel the need to pick sides, simply because they know who longer. So I decided to ask this community for an opinion, and hope I'd get some answers, biased or not. Recently my lovely wife had her birthday celebration, and I noticed sil's child (14m) was looking upset, so I pulled him aside to ask what was wrong. We weren't close, but had a civil relationship and I fixed his bike a few times. He mentioned he was upset my wife hadn't responded to his message yet, when he needed my wife's help on something. I tried to ask what he meant, but he just shook his head and ran off. I shrugged it off, deciding to talk about it to my wife when the celebration was over for she had been so busy at work and stressed, I wanted her to have this day.

Move over to the next morning. We're sitting down, having breakfast when I mentioned what sil's son (we'll just call him Anthony, fake name) said to me. My wife took out her phone and gave it to me. She said she didn't want to look at the chat. I looked through the messages, seeing he was constantly venting to my wife. I won't share what he was venting about, but he was messaging her everyday and it got to the point my wife felt mentally drained and unsure what to do. She stopped responding to him three days before the birthday party. I told my wife he's not your responsibility and sil and her husband is. If they aren't around CPS and a therapist needs to be involved. This was when I saw relief in my wife, and told me she had been waiting for someone to say that to her.

That night, we sent a long message to sil and her husband (we share a group chat) about Anthony coming to my wife for help and mentioned if they aren't in the place to take care of their son, they need to do something to help for my wife cannot constantly be his rock. Sil called my wife selfish, and I immediately shut it down by mentioning this was draining her own mental health. Her husband was no help either, not giving any crap about their son. The conversation went longer than it needed to, so I told them their son needs to stop speaking to my wife and left the group chat along with my wife.

My wife tells me she is thankful for my help, and admits she hasn't been resting as well lately due to fear of what her nephew would do. I told her it was alright. I love my wife you guys, and I refuse to let anyone hurt her. But did I screw up something? There's a pit in my stomach, acting like I was the one who fucked up.

People of reddit, lend me some advice. Tell me what steps I should take next.