Currently taxpayers return is

-$2,474 owed fed and $19 refund state. 

Daughter is 22 and was a student and claimed herself. 

If taxpayers claimed her and her 1098t their refund would be $596 fed and $101 state. 

The daughter from claiming herself got a refund of $1,639 fed. She W/H $639. This is tax year 22. If I 1040X the return and the daughters pays back the $1,000 they would still be up $2,070 fed unless the interest and penalties is bad. 

I did the ITA and she can be a dependent. How would I even go about guessing what the daughters fees would be?