That language means you can go back to court for the Judge to consider the issue whether support should be issued and whether it should be applied retroactively. Whether it will go back 11 years will depend on the Judge, but there is a possibility since the court reserved jurisdiction over the issue.
Right now you need to prevent custody if you can show that the current living situation is harmful to the child, that would be the only way to avoid you from being paid child support. Although a child her age has a say, the court will look at all circumstances to see if the child's request for a change in custody is best for the child.
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