Road Trip by Mary Kay Andrews

 Maeve and Theresa are squabbling sisters. When their beloved mother dies, they find out she had sent all of her savings to--and mortgaged her house for--a sleazy televangelist. But she did leave them money for a trip to Ireland to learn more about their roots--along with a painting that she claimed was worth a fortune.

The women head to Ireland and are very successful at uncovering the family history as well as the story behind the painting. They also incur someone's wrath and one of them falls in love. It's a rollicking good tale.