She is going to need a way to support her kids, so more power to her. No one forces anyone to go to these musicals, watch tv shows, etc, so I could care less. Other celebrities are just a greedy as her, except they buy themselves overpriced toys as opposed to a dozen or so kids.
Exploitation is an overused concept. How is she exploiting her kids? Not any more than any other parents exploit their children into acting. Besides you we are not their parents, so there is really nothing we can do about it. CPS has their eyes on celebrity children more than on regular kids anyway.
Is "Octo" (as she's called in the piece in the link below) even getting anything for this? (More of a rhetorical question. I, personally, don't see that as my business.) The guy's musical is about people who "can't get enough", and he's including other infamous people in it.