Our daughter claimed her daughter (both live with us) but wants to amend her taxes so we can claim her. We have both already filed are taxes. Can they both be amended?

We provide more than half the support of our granddaughter who lives with us.

I prepared both our taxes forgetting to claim her on ours per permission of our daughter. 

Her refund is being held as she apparently is behind somewhere on her student loans. 

Can I amend our taxes?  Or will the denial of her refund make us ineligible for doing so?