Find an empty promise and stick by it.
Her love has been like a pie. When her son was born, it was all for him. He took every piece, and there really was none left for anyone else. She remembers being so surprised, so amazed. She knew chemistry was a big deal, but she never knew how chemical love could be. She thought love was so much more.
And maybe love was so much more. She couldn't feel it, but didn't it carry her through that first year with her relationships intact? She couldn't feel it, but it held her marriage together, and kept her from giving away her cats.
And now, her love is not like a pie anymore. It's back to being that miracle thing where the more you give, the more you have...which makes complications so possible.
Why would a person who loves her husband write a letter to an ex-lover? Why would she indulge her feelings of unresolved business? She knows that loving someone else doesn't mean she loves her husband any less. But she risks hurting him. What's to gain? What could possibly be gained that's worth risking his heart?
She does not want to have an affair. She wants to go back in time, and make something right between herself and a man who had been the love of her life. She wants to correct a dishonesty. She wants to go back in time and have her heart broken the right way, so that it can heal the right way.
Right now her love is a crooked finger. Is that good enough for her husband?
But is it a crooked finger? It wasn't really a pie when she it felt it was a pie. Why would it be a crooked finger? The crooked finger is her thinking.
Love is invisible. Love is a body without a body--Wallace Steven's empty sleeve fluttering, Rilke standing on fishes.
I hope she will trust.
EDIT: tiny change to above prose