Former girlfriend began messaging prisoners, hoping to help them reform since she's studying law. She began talking to someone and started developing feelings, calling and messaging every day and night and flirting, even talking about progressing it

I wish her the best but she keeps screenshots of her call logs with him, messages he sends, telling me it's what we had but 10x better with him

How should I approach this? Ignore her messages and wait until he fumbles or should I act indifferent and make plans?