leave (spoiler)

She loved her husband as well I'd say. Like she said, what her and Robert had could well have not worked outside of those four particular four walls on those particular four days etc etc.

I think if she left with him they would always try to get back what they had over those four days. The circumstances is what lent itself for their affair to be as intense as it was. In reality, she would've missed her family, and possibly blamed Robert for her choice to leave them, and being with just one woman would've unsettled him by being so settled.

This way, their love will always stay alive within the tragedy of it never becoming something more--if that makes sense. It was profoundly beautiful even if it only lasted a few days.
~Keep some room in your heart for the unimaginable~

Nah ... listen to the scene where they had the candle-lit dinner. What they had during those four days was not something that could last. She would never be able to forget her husband and kids, and they’ll face scorn in society because of her. She also didn’t know Robert totally; it was just 4 days. She didn’t know any of Robert’s faults and bad habits etc.

She couldn’t have just left with him and live happily ever after.