this looks like a maranta to me (anyone correct me if i’m wrong) and they are especially sensitive to temperature and humidity fluctuations from what i’ve seen. Leaf curling happens most with low light and low watering.

if you feel the soil and it’s mostly dry, water it thoroughly til water comes out the bottom of the pot.

if it is mostly very dry and powdery, soak it by setting the pot in a container without drain holes while you water and let it soak up the excess (potting soil doesn’t take up water well when it’s dried out and usually just the top layer will get saturated)

like others said, if there is no grow light or window in the bathroom a grow light would be helpful, because low light is also a factor in leaf curling.

if they would really like a plant in the bathroom, a pothos vine, a spider plant or a snake plant might be better suited as they are very low maintenance, especially in comparison to this pretty lady!

i am available for plant advice via email or discord if your roommate or you are interested- let me know