Hi,

Your daughter in law’s plant looks like a Calathea, probably a type of Rattlesnake Calathea. The main thing this plant needs is high humidity and good quality water. If her household water is high in fluoride or chlorine, let it sit out over night before using it. She should never use water that has passed through a softener (too salty).  You can read all my care tips for a Calathea plant in the Popular Houseplant section of the website. The picture is of a different variety, but the care is the same.

http://www.houseplant411.com/houseplant/calathea-plant-how-to-grow-care