Avethana doesn't much like the night. She'd liked it fine when she was a little girl, when it meant her father's return from his work, hugs and explanations of the building blocks of the world, when it meant being told stories from her mother while snuggled up in bed. Now she's older, away from her more quiet home town and her parents, and far more aware of some of the dangers night might bring. As such, she'd rather avoid being out at night, and feels a vague sense of dread whenever it happens.
But today her hours ran well past sunset, and well. What would she have told tell the patient? 'Can you put your child's whooping cough on hold, please? It's getting late, and I need to get home to hide behind my wards before night falls, because I'm scared that a monster might pop out of nowhere to eat me.' Yeah, no. Putting aside how she's not going to abandon a kid to cough themselves to death when she can fix it, that is exactly the kind of thing that leads to being eaten. Her best defense is the one that served her mother well; subtlety. No one needs to know that she's keeping the wells and pumps of the city clean of cholera with magic. She can help make things better without getting herself killed. For now, it's best if no one thinks she's extraordinary at all, and she pretends that the night is not full of terrors. So as not to alert the terrors that she's onto them. Later, she can take in some students with a plausible cover besides 'magic.' Until then, patience. Patience and subtlety.
Unfortunately this does mean that sometimes she's stuck walking home alone at night, because there's no reasonable reason for her to flee with the sun. She walks quickly, and takes shortcuts.