You could always get the balcony seats.
I haven't been up there in years, but I believe that they are about $36. It's not a great view, it's not comfortable, and the seats are very high.
So perhaps you can but them, then complain to an usher that your mother has vertigo or soemething. They will let you move down to the mezz if there are seats.
"If you are going to do something, do it well. And leave something witchy."
-Charlie Manson