Your life hasn't been normal since the day you came out of the womb. When you thought you'd found some normalcy after marrying Bruce...you found out about his vigilante children. But "normality" is subjective, right?
Plus, you can't really judge either with a past like yours. A past that you had successfully hidden up until this point. You were in the kitchen, trying and failing to cook something (there was a reason that job was left to Alfred) when you heard it. A familiar trashy beat and the voice of a 20 year old coming from the TV in the living room. WHO found your concert tapes?!
Sure, some kids find corny childhood pictures of their parents. But nothing beats the embarrassment of your children finding out about your trashy popstar days. You drop everything and rush into the living room, snatching the remote from Damian.
"No!" You exclaim, trying to eject the tape, but he and the others had already seen a good portion of it. Dick spoke up.
"Mom...you were a popstar?!"