The Life You Longed For by Maribeth Fischer

Grace's three year old son, Jack, has a terminal illness. She spends her time taking care of him and her other two children. Her respite is her extramarital affair with high school love, Noah. When Grace finds out that someone has filed a report with child services saying that Jack is a victim of Munchausen by Proxy, the family's world is turned upside down. Grace has always been her son's fiercest advocate (she has a background in epidemiology) and now it turns out that someone is trying to use her love and commitment to her son against her. How will Grace and her family persevere? The subject matter of The Life You Longed For is serious, but Fischer writes a novel about love and how it affects the choices we all make.

This novel reminded me of the books of Caroline Leavitt.