@sherlock0790 I guess, I'm not following with what you mean. "fraud"? What? They didn't lie on any documents that got her into school as you can see in the bottom right of the document it shows her "academic history" starting from the 70s, so I'd assume with that the people that let her get into their college know how old she is, that doesn't mean they will advertise it all over campus or even when she had to give her ID to the police in like the 3rd chapter. So, basically all they are doing is just not telling people.. Which in reality it isn't anyones business.
The MC just doesn't want people to find out about his mother, because he thinks it'll turn there life into a freak show. I'd agree with that action to an extent, but not to go as far as they have.