I would have 2 guesses:
1. A fox got them both.
2. More likely is that because this is nesting season, this is the perfect time for her to start sitting on her nest. I bet Miss Hen was laying a nest full of eggs hidden away somewhere that you didn't know about (they can be very very sneaky about this). She probably began sitting on it and then Mr. Tom has now followed her and is just hanging around with her nearby her nest (she probably wishes he'd go away since he's giving away her spot to all the potential predators). You could wait 28 days and see if she returns with poults. However, my advice would be to go on a search, find her and take all her eggs and put them in a turkey-sized nestbox in a pen (without Mr. Tom) and put her in there alone and let her sit on them in that pen. Just make it an appealing, dark, protected nestbox. Otherwise, if you let her sit on her nest out in the wild, she's likely to get killed by a dog or fox and if she hatches poults in the wild she's very vulnerable and it's likely they'll get attacked and killed by a hawk or a fox.
My advice: I would go look for her -- along any wind-rows, in tall grass or brush (preferred by turkeys), in a low pile of sticks, in a dark corner of a barn, on any little spot hidden away that she liked, etc. Also, if you are near woods, hens like to have soft leaves for their nests and will cover them up with bits of leaves and grass. When I found nests they were completely covered except always one half of one egg would be visible (I guess to find the nest again!).
From experience, I know these broody turkey hens will sit perfectly still even if you're 6 inches away, trying to blend into the background. You could be right on top of her and she wouldn't move. Fortunately you have Mr. Tom to give her away. If she came back to eat she's probably not more than several hundred feet away. I don't think she'd be more than 6-700 feet away so that might help you know where to look. Also, mine hens usually jumped off the nest in the morning and ran around desparate for food and water for a few minutes each day before running back to the nest.
Let us know what happens!