My (23M) girlfriend (21F) messaged an ex. Should I be worried?

My girlfriend and I, who have been together for seven months, ended up going through each other's phones (I know, not the best idea). After some thorough searching in late December, I discovered that she had texted an ex about hanging out back in October. When I confronted her about it, she explained—despite our previous discussions on this topic—that she felt I wasn’t that into her during that time, and she genuinely thought I might leave her since we had a tough month. To cope with those feelings, she reached out to him for attention, knowing he was always eager to engage with women. I found these messages by texting him from her phone, asking “Hey, I forgot where we left off” and “I deleted our messages; could you refresh my memory?” He was very eager to meet up with her in person and eventually sent me screenshots of their October conversations, where she mentioned hanging out on Halloween and made similar plans a week earlier. He remarked that she would ask to get together but would then completely ghost him. So, does this mean her texts were purely for attention, or was there something more serious behind them? This situation really made me reflect on how I had made her feel.