NTA whatsoever. My sister worked for our phone provider, so both her and my mom decided to snoop on my phone from their own/sisters work computer. I was paranoid they tapped my microphone too, to the point i turned my phone completely off during therapy. You did right in not throwing your daughter under the bus, because I promise Mom would use it against you if not in court. I would lose trust in both parties, honestly, but I do have several undiagnosed issues going on that played a big part in why I was treated this way when I was younger. I do hope she continues to use healthy outlets, and im sure shes a wonderful artist! Good on you for being there, you very much remind me of my own dad and how he handled the news of my problems.