She came here illegally as an adult so knew full well she was committing a crime. She continued to commit the crime of staying here every day for the 24 years. Nope, sorry, no sympathy. Kick her out immediately along with her anchor babies.
Kicking out American citizens is a non-starter. Send her back, but allow her adult AMERICAN children to sponsor her return in five years or so.
I've said for years that birthright citizenship should only be conferred upon children born of foreigners LEGALLY present in the U.S., but until the law is changed, her kids are citizens.