State tax filing

My 529 plans are for my grandsons (ages 10 and 12) who live in Geneva Switzerland. They are both U.S. citizens and live with my son. I withdrew $10K from their 529 plans and sent the money to my son, who paid their tuition. There is nothing in Turbo Tax Premier that discusses this situation. I did receive a 1099Q from T. Rowe Price, but Turbo Tax indicates I must pay U.S. taxes on this distribution. It would appear that I may have to file by mail, vice electronic so that I can include the tuition receipts.