Actually, Pietro and Wanda are Mutants and Magneto's children in Disney related media (The Avengers: Earth`'s Mightiest Heroes to be precise). No relation to Polaris has been accounted, though (and even in the comics, it depends on the writer if Polaris is related or not to Magneto).
Elsa is not a Mutant since her powers are implied to be magical, not genetic. However, I should add that the "Mutant" category of this wiki doesn't refer to the Marvel definition of "Mutant" (those who are born with the Mutant gene as opposed to those who acquired their powers via an accident and/or experiment), but to all those with unnatural traits, be it from birth or acquired.
FREEDOM OF SPEECH!!! and besides Polaris appears in Wolverine & the X-Men and according to the producers it's in the same universe as Avengers EMH. Also QS & SW are Magneto's kids in the EMH comic and Disk Wars.
Your attention please, Elsa is not a Mutant and nor was there any mention of it in the film or any official websites. Please do not proceed anyfurther or I shall be forced to take drastic meassures. Magic users are not mutants, mutants to me are for superheroes.
Apologies, that sounded wrong, sometimes I can get very protective when ongoing false editing doesn't stop. Forgive me if I disturbed you in anyway, Let me sound that out again.
Could you please stop inserting the Mutant category to the Elsa article because she is not a mutant, she's enchanted and even if it wasn't me reverting your edits, the Administrators too would disagree with it.