Sounds hard to believe even with today's shortages.Daughter driving on very worn tires now as no new ones in her car’s size available anywhere.
If original size unavailable others in same diameter will fit OR
move up (or down) a rim size. Most any tire store should be
able to order the size she needs and have in a few days.
If not, order online from Tirerack.com. Tires or tire & wheel pkgs.
If getting wheels & tires to get different diameter be forewarned
most of the wheels made in China. One brand from Poland is
Rial, better quality and warranty than China brands.
I recently changed from 17" to 15" wheels and Discount Tire
had 15 inchers in stock. Fifteens not in much demand these days.
Definitely cheaper than 17s though.