A 20 ga with 3" heavishot would do well on a bird. Even at 200+lbs, I hate patterning 12ga turkey loads. Stick with the 20 for her, just make sure they are within 40 yds. My
good luck.
As for a location, can't help as I am on the west side and don't know that area at all.
Scud
Try that, and maybe even get some lighter loads, I had the wife go out with me last year, using a H&R 20ga with plain old #6's She popped hers at 20 feet hardest hit turkey I've seen even the one I got with #5 Hevi shot at the same distance, plus get her as comfortable as possible, if you got a blind and some dove stools/chairs that's perfect those gals have a hard time setting more than an hour on hard ground with a wind blowing. And don't get super focused on the kill , we got a hen to walk in between us at one point and that was all the wife needed to get hooked. Just like us, they dig just seeing and hearing them and when you get a hen or tom within feet of her She'll feel that rush. My wife is so hooke now I may never get to hunt by my self again

Although witha pretty lady next to you out in the woods with nothing to do......well there's always something to do

Good luck I think she'll like it once the action starts