From the information you provided, the answer would be $9.60.
The tax, $0.63, is added to the cost for all three cards, $8.97, thus making the final amount $9.60. $8.97 plus $0.63 equals $9.60.
Another way you could do it is dividing everything by 3, as she bought three cards. $8.97/3 is $2.99, thus making each card $2.99. $0.63/3 is $0.21, thus making the tax on each card $0.21. Therefore, $2.99+$2.99+$2.99+$0.21+$0.21+$0.21 is $9.60.
Hope this helps!
