If they want and can qualify/complete the emancipation process (which includes financial self support) then take that route. Then the minor can have any surgery they can afford. Until that time or the age of majority my position would be no.
https://en.wikipedia.org/wiki/Emancipation_of_minors
https://en.wikipedia.org/wiki/Emancipation_of_minors
I don't have an anger problem, I have an idiot problem.