What happened with her sister?
Her sister seemed to be a regular part of her act, but this show appears to be deliberately excluding the sister.
In the first show, a fictional best friend since kindergarten shows up. This friend looks and acts remarkably like her sister, but they make it clear that she is not. Then in the third episode, the parents talk about Maria being their only child.
Did her sister threaten Maria with a cease and desist order or something?