Who is Patrick, Conor, and Colleen Grogan from Marley and Me and what is their importance?

Patrick, Conor and Colleen are the children of John and Jenny. Patrick is conceived in Ireland while his parents are on vacation, so his name derives from the place of his conception. Seventeen months later, Conor arrives following a scary pregnancy. Jenny suffers severe cramping at twenty-one weeks and is hospitalized for twelve days while doctors try to stop her contractions. When she is released from the hospital, Jenny is placed on bed rest for the next three months. The day after Jenny is released from bed rest, she experiences cramping again and goes back to the hospital where she delivers a healthy baby boy - Conor. Colleen completes the Grogan children. While most people think that John and Jenny are crazy for having another child after Jenny's difficult second pregnancy, Jenny is overjoyed to have a girl, and John relishes having a daughter.