I agree with Mike about this.
As regards the issue that the topic was originally about: no, I don't think underage girls should be allowed to have access to abortion without one of their parents or guardians being informed/involved.
It is a medical procedure, and as such carries risks to her physical health, and also to her mental health and emotions, because of the circumstances which are much more emotionally charged than those surrounding other medical procedures.
You aren't even allowed to get your belly-button pierced without parental/guardian consent if you're under 16, and yet you're allowed to have the child dragged out of your womb? That doesn't make any sense to me. You're not even allowed to drink alcohol in a pub until you're 18, supposedly.
Naturally, there are some circumstances where a girl's parents don't want what is best for her; families where the parents are cruel, unfeeling or abusive. But these parents, as well as being the minority, obviously have problems which mean that the whole circumstances need to be investigated; their children will already be suffering because of their situation and it's not possible to say that either choice 'abortion' or 'no abortion' would do anything to alleviate this.
If the girl's health is at risk because of the pregnancy, then of course an abortion should be performed.