Why does Patina do Maddy's hair every Sunday?

Patina does Maddy's hair every Sunday because Momly cannot do it. Momly never had to deal with black hair, and there is no rule book for white people to know how to work with black hair. The other reason that Patina does her sister's hair is because they go to see their mother on Sundays, and she wants Maddy to look nice for their mother.