Julie -
I ate most of my adults this year (we had a big thanksgiving dinner for both our families, it took all 6) but I have had many adult turkeys, for a long tim, and am hatching replacements now.. (Ok, I'm a farm kid in my 40s, now you know.) Some turkey hens, like some chickens, are good setters. I've had several do the setting, however, I always do the raising, unless a hen had proven herself, and I keep her alone with her brood. They are rather dumb mothers, to be frank.
Like peacocks, they'll fly up or away rather suddenly, and leave the wee ones behind. They stand on them, loose them in puddles, and let the cats eat them, most of the time. My mom had a wild breed turkey hen that hatched and guarded like mad, could trust her with 30 cats around. She was the exception. Another hen I had several years ago, a white hen, would sit and mostly guard, but it was prudent to keep her in a pen, with fine wire around the bottem 18 inches to discourage cats from reaching in.
Why don't you try her out, let her set, then pen her alone. If you have cats, forget it, it's probobly not worth the risk. Like all mothers, the first time is the hardest, but if she does pretty good, she'll be better next year. If she leaves the eggs in 14 days, forget it forever. This is all just my opinion. You know your bird better than me.