Secret Sisters

TFQOD: So I have a secret sister at church. We are talking about in the car on the way home tonight. The girls keep trying to guess who it is and I am not telling. Then they want to know how old you have to be to have a secret sister...I tell them you have to be out of youth. To which Emma replies "No fair...I'm not even in youth yet." And Holly says.."I know right. And I'm stuck with 2 regular sisters"