I don't know and neither do you.
What I do know is that the administration was not giving a reasonable amount of time to make decisions nor was it providing translators or meaningful opportunity to seek counsel. So if she "chose" to take them, it was almost certainly not an informed one. And of course, she's put to a Hobson's choice if the administration says (as they surely did) "you'll never see them again."
The obviously correct thing to do was let the mom stay in the country with her citizen babies, given that she was harming nobody. But y'all are so thirsty for deportations -- it's manic. It's Lebensraum v 2.0. So of course you want to be cruel and harsh, because you fundamentally don't respect their humanity. To you, they are just "illegals."