Not enough info. It depends really on the stallion. Is he well managed and manageable? Right now, she's 7 months pregnant so there's no worries about accidental breeding, in fact, she'd probably humble him pretty quickly if he tried to get 'smart' with her.
I have 1 stallion, 6 mares & 2 geldings (who were not unmanageable stallions, just didn't need more stallions) and one foal on the ground and one more coming. I keep the stallion in one stall in the barn, one gelding across the aisle and, when the other gelding isn't out for training, I keep the 2nd next to the stallion. Just so the stallion isn't tormented, I keep that stall next to him empty when the one gelding is out. The mares have the remaining stalls in the barn. I expect that stallion to mind his manners, no rowdy stallion antics at all, or I'd have a 3rd gelding. The mares are expected to mind their manners when in their stalls too.
I keep pregnant mares out with the stallion when they go out on pasture. They teach him better manners than I ever could. Would I send a novice out to the pasture to fetch the mares? Well, in my case, yes I would because there's no way that stallion will act stupid around a human. If the stallion was aggressive, no I wouldn't. Actually, he'd become a gelding quick, but I understand the cultural differences.
My stallion is extremely quiet and gentle but, yes you can 'feel' his presence. When you say that about the Friesian, what are you saying exactly?