Did you go to turbotax.ca/activate to use your code before you started your returns? If you didn't you can enter the code in the coupon code box on the payment screen.
 

Also, if your daughter has something that's not supported by Deluxe, then her return will be upgraded and she'll have to pay the difference. You can see what each version supports on our website: https://turbotax.intuit.ca/tax/software/online