Your question's a little short-fused for filing this year!!
If her divorce decree states that she is the one who is allowed to claim the children, with no further stipulation such as if all support payments are current, she doesn't need a form 8332 from him. She does need to send copies of the following pages of her decree with her return:
1. Cover page (write other parents social security number on this page).
2. The page that states you can claim the child as a dependent.
3. Signature page with the other parent's signature and the date of the agreement containing all the signatures.
