Sophie and her adoptive father, whom she calls "My Michael," are family.
Michael is a good singer, not a great cook (though Sophie likes the "burned-y bits") and he takes care of Sophie when she's sick by giving her crackers and ginger ale. Sophie might have put blue paint in the blender and left the lid off, and drawn pictures on their apartment door...but Michael says she's his universe.
When Michael gets sick, square crackers and ginger ale don't help. Sophie gives Michael the Big Dipper for his wall, and that makes him smile. Even though Michael doesn't look sick, Sophie knows the truth. And just like he's there for her, she'll be there for him no matter what.