Maybe she was a drug using freak or maybe he just wanted to take the kids to hurt her. Doesn't appear as if she ever gave up trying to find them though.
I don’t disagree with her being upset, maybe she wants closure. I disagree with the complete interruption of the two children’s lives, on the basis that she was supposed to have the children and now doesn’t.
It seems more, than glancingly, like the Solomon baby dispute... “I’d rather completely disrupt their way of life, thrown into turmoil, and hassle my ‘children’ who are basically grown adults (who—at least one—have said they don’t want a relationship with me), for their own good, and so we can have a fmaily I never got.” After all, they are almost within her unnamed “grasp.”