I think any pregnancy of an 11-year old poses a great danger for her health, both physically (even if these dangers are not life-threatening) and mentally. I think 22 weeks is too late and the abortion should ideally have taken place earlier, but it should be allowed nonetheless. In general, I'm mostly not for going down the "mentally problematic = allow abortion" road, because next thing you know someone wants an abortion because she can't party all night long anymore and that's sooo mentally threatening, but when it comes to girls under 16, I think an exception should be made, for the mental issues and the physical issues combined can really ruin such a young girl's life. That's not a really consistent position, but in the abortion debate, any truly consistent position seems problematic and inhuman to me, so I'll settle for a compromise. (normal Dutch)
It is not circumstances, but a woman's live. It is easy to reduce this to something "principled" when you are a man and will never be in a similar situation.
I am sympathetic to your position in general, but this is not an argument. Like it or not, there are lots of women who take the same stance. The idea that someone's gender is even remotely relevant in the abortion debate is based on some very problematic assumptions. You don't have to be able to have a child in order to have an opinion (more specifically, a negative opinion) on abortion.