My daughter got glasses almost a year ago and she is twelve years she can't see perfect in glasses anymore she is nearsighted why is that happening does she need stronger glasses is that normal?

Its normal for a person who is still growing to need new glasses every year, or even sooner. Just as their body is growing their eyes are changing, which makes their vision change to. Because of this a new prescription is needed. Even adults who are not growing will need to get their eyes checked every year in case their eyes have changed.