There should be one exception to having an abortion for underage girls without parental permission, and that is in the case of incest. Anyone who needs a medical procedure who isn't a liberated person needs parent/guardian permission to be treated, get a prescription and the same process should be followed for getting an abortion.
Parental consent should be made mandatory for any underage pregnancies before they are able to get the abortion. I think this will one, cut back on some of the abortions and two, the teen should not be making such a hard and difficult choice on their own. They need guidance.
So if she's not mature enough as people argue then logically parents should be allowed to make her get an abortion against her will. This is both a logical consequence of the other sides arguments and so horrific that to avoid such horror and still be consistent we should just let her make her own decision.
She should not need parental consent as it is her body, and her choice whether she wants to/is able to bring up a child. It is a difficult decision and she does need guidance in it, however it is still her own choice - no one should be able to say whether she can or can't have an abortion. If parents wouldn't allow abortion, so many problems could be caused - she may not be able to bring up the child at such a young age which wouldn't be beneficial to the child or the mother, it could even cause a scenario where underage girls will go to desperate measures to get rid of the baby - abortions performed by unqualified people for example, taking matters into their own hands and even maybe doing stupid things like drinking excessively to get rid of it so her parents don't find out. There are so many things it could cause, so I don't think it should be mandatory for parental consent for underage abortions.