The Herald's Rest.
Hermione doesn't often come in here, not since receiving an odd look when she'd first asked for just some water (really, given how young everyone here seems to think she is, she'd been surprised that the surly bartender had thought she'd wanted something harder). But sometimes it's a nice change of pace, sitting among the mostly quiet chattering of the other patrons and enjoying the fire as she reads or looks over her notes. Presuming, of course, that no one is foolish enough to have too much to drink and try to bother her. Talking is a distraction she'll accept with no fuss, but Merlin help anyone who's had enough alcohol to think she's open to anything friendlier than that.
When she'd first arrived at Skyhold, the stables had seemed relatively empty and were a fine place for practicing her magic without risking hurting anyone. She'd thought she could do the same now, only to find that there are considerably more horses - and, er, other creatures - residing there. Magic might only frighten them, she decides, but they're so pretty that she can't help visiting with them for a bit, getting as close to them as she dares. It's been years since she's ridden a horse, but she's entirely certain that these mounts aren't exactly the type that would trot gently along a given course for an inexperienced rider, so she isn't even going to ask after something so silly, even if the interest is clearly there in her eyes.
Courtyard, not too far from the healing tents.
When the stables prove not to be the best place to practice with her magic, Hermione decides that it might be best to find a little corner close to the healing tents instead. At least then there would be other mages around, and so it was less likely that anyone who stumbled across her would look at her disdainfully. And if anyone gets hurt, a healer wouldn't be too far away. Of course, she highly doubts that anyone would get hurt just because she was unsuccessfully attempting to transfigure leaves and pebbles and whatever else happens to be in the vicinity. Transfiguration doesn't seem to be an aspect of her magic that's carried over into Thedas, or at least Hermione can't manage it without more practice, given that she's growing more and more frustrated as she continuously taps rocks and other objects with what looks like a stick, muttering to herself in exasperation.
Library. Because of course.
If you've been to the library, you've seen her. Whether you know her and enjoy talking to her about rifter politics or think it's entertaining to scandalize her or have never bothered to approach her, Hermione can more often than not be found in the same little niche in the library, nose in a book or a quill hastily scribbling down notes. Or even, occasionally, dozing off, since she hasn't exactly claimed any sort of sleeping space for her own and more often than not loses track of the time when she doesn't explicitly have somewhere to be.
Hermione wanders, and while she tries to be careful, sometimes it takes her places she just shouldn't go. If it doesn't look like a private room or setting, it's safe to assume that the young witch has made her way there, likely looking for a quiet place to read or do magic or just to get a few moments of silence. And while she doesn't often journey outside of Skyhold, she can definitely be tempted beyond its walls if she has the right incentive, or the right company.