Most show stalls are set up so that the horses can’t touch noses (doors are on one side so they can’t lean over the door and reach each other). Unless she’s particularly tall and decides to stand up in the corner and look over the partition, you’ll likely be fine. If you get the two end stalls (definitely request this ASAP as many shows give end stalls to trainers with set ups), you can put her on the end and then have the tack stall between her and another horse.
I always bring extra, extra hay. You can bring it home if you don’t use it, but it keeps them occupied so they worry less about what’s going on. If she’s food motivated you can also get her a hanging treat ball/toy if she’s the type that would enjoy that.
Other tips for showing away from home from my mare that lives on 24/7 turnout are:
Hand walk as much as you can/as much as she wants. I take mine for a spin around the show grounds on move in day, then again at night check each night, and my mare won’t eat breakfast without a morning walk first. 

I also bring extra feed and if she’s not the food motivated type, something yummy that will keep her calories up. For instance, my mare sometimes gets a treat of soaked Timothy pellets at home. She all but completely goes off her grain at the show, so I bring pellets along to get something into her.
If she’s aged, wrap legs every night to ward off any inflammation/stocking up.
When you do night check, make sure the lights are off. It might take some hunting to find the switches (do that in the daylight). Lots of people leave the lights on and it drives me nuts. Show horses often are sleep deprived and if she’s used to being home, she’ll need all the help she can get sleeping in a new place
Have fun!!