Hmm, a cute brunett planning a road trip to far distant land of OP. Your e-mail/phone will get overloaded with folks wanting to tag along, or asking you to make detours.
There's a gal at the box-office all day long, just avoid lunchtime. And, a road trip to scout out the parking, etc. if you've never been there, is an excellent idea. You can figure out which entrance/shortest walk might be best for your Nan, vs. driving around a bit the night of the show and ending up parking on the far edge towards Colorado.
Or, if you're ok closing a deal over the phone
, call the box-office gal back, she can select specific days/seats for you.