A restrictive clause is essential to the meaning of a sentence and should not be set off by commas. In this case, the sentence that contains a restrictive clause needing commas removed is:
"My little sister, who loves to dance, will not teach me any of her moves."
The clause "who loves to dance" can be seen as providing essential information about the sister (if there are multiple sisters), indicating which one is being referred to. Therefore, it should not have commas.
The other sentences already have their non-restrictive clauses (which provide additional, non-essential information) correctly set off by commas.
To correct the sentence, it should read: "My little sister who loves to dance will not teach me any of her moves."