The McIrish family is a family that's part of the Single Moms household. The family consists of Fiona McIrish who is a single mother with her teenage daughter, River McIrish. Her friend, Molly French, and Molly's toddler daughter Sandi also live in the same household as their roommates. It's unknown who is the father of River, nor is ever mentioned. Fiona is an adult at the beginning of the game and River is a teenager six days away from becoming a young adult.
McIrish: A pun on Irish. Irish-of or relating to Ireland, its people, or the Goidelic.
Fiona: Fair, white, beautiful; Wine.
River: a large natural stream of water flowing in a channel to the sea, a lake, or another such stream.