http://www.cnn.com/2007/HEALTH/10/08/hysterectomy/index.html

For the full story. It seems to me that the mother is doing whatever she can to make sure her daughter's life will not be disrupted by a process that she is not likely to understand or even ever use. If the young lady is that severely disabled then she will most likely live at home and never get married or have children, so infringing on her right to reproduce is a moot point.

In reference to the previous comment, saying:
"a process that she is not likely to understand" I would just like to point out that according to the article, the girl has Cerebral Palsy. This causes movement and motor skills problems and does not have any effect on intelligence. There is no reason to assume she would not understand the process. But that's not the point in question anyway. If this is carried out in this particular case, who is to decide what the guidelines and cut off point is to start neutering people without their consent.

"The short-term pain and discomfort we can manage with painkillers. We will be able to manage that pain much better than menstruation once a month, when Katie cannot tell us 'I'm in pain.'"

The mother's comment seems to indicate that Katie cannot communicate. If that is the case, she is unlikely to be able to consent to the operation when she is of age.