If she remains DFd and her children get baptised, they will be required to shun her. This will be at least one reason why she will want to go back.
This quote is from their official website.
Cutting off from the Christian congregation does not involve immediate death, so family ties continue. Thus, a man who is disfellowshipped or who disassociates himself may still live at home with his Christian wife and faithful children. Respect for God's judgments and the congregation's action will move the wife and children to recognize that by his course, he altered the spiritual bond that existed between them. Yet, since his being disfellowshipped does not end their blood ties or marriage relationship, normal family affections and dealings can continue.
The situation is different if the disfellowshipped or disassociated one is a relative living outside the immediate family circle and home. It might be possible to have almost no contact at all with the relative. Even if there were some family matters requiring contact, this certainly would be kept to a minimum, in line with the divine principle: "Quit mixing in company with anyone called a brother that is a fornicator or a greedy person [or guilty of another gross sin], . . . not even eating with such a man."
Chris