I see this as a woman who was emotionally vulnerable and didn’t have a lot left to live for aside from her mother, and who had followed the rules and life hadn’t really worked out. She felt romantic desire and adoration and uniqueness for the first time in a long time, if not the first time ever, and the aspect of forbidden activates more brain chemistry (weren’t we all teenagers once?) and this all gave her something extremely powerful to look forward to. Her ex husband died (she is a widow in my eyes, given their amicable relationship), the house was empty, she had worked enough … I find it completely understandable that she submitted the retirement paperwork. She was a rule follower right up until the moment she wasn’t, but she thought about that moment for years, I bet this investigation reveals. I think this relationship basically gave a lonely vulnerable woman a reason to live.
I’d have a hard time as a juror sending her to jail. She needs mental health treatment, a purpose and more reasons to live.