His secret wife / Lisa Timoney.

"What happens when his secret wife is the only one who can save your child? Elle has the perfect life. A hard-working husband, a clever little boy, and a gorgeous home in a quaint neighbourhood. Jen also has the perfect life. A passionate relationship with a doting husband, a creative little girl, and an exciting career. When a strange coincidence throws them together, they become close friends. But then they uncover a shocking truth: they share the same husband. As they both grapple with this devastating revelation, Elle receives worrying news about her son's health. When things go from bad to worse and Elle has no one else to turn to, will Jen help the woman who shattered her world? And can Elle trust the other woman with her child's life?"--Provided by publisher.