No. If the box 1 amount is fully covered by qualified educational expenses (QEE), including room & board, you do not have to even enter the 1099-Q, in TurboTax.
When the box 1 amount on form 1099-Q is fully
covered by expenses, TurboTax will enter nothing about the 1099-Q on the actual
tax forms. But, it will prepare a 1099-Q worksheet for your records, in case of
an IRS inquiry.
The QEE must be for the beneficiary of the plan. That is, you may not use student #2's expanses against the 1099-Q from the 529 plan that student #1 is the beneficiary of.
Furthermore, you may not double dip. You may not count expenses covered by scholarship or used to claim an education credit against the 1099-Q