What’s going on?

If the cup is lighter thats usually a sign its low on water, but the best way is to just stick your finger in the dirt and dig around a bit with your index finger....feel the dirt and if its dry then water it, if its still damp after you dig around a bit and get a few inches down near the sides of the cup/pot- then its fine for another day. Some times you gotta get your fingers dirty to learn more about whats going on under the surface of the soil, dont worry about disturbing the roots- just dig slowly and around the edges and feel it. Id give her a light water with a spray bottle right on her roots and see if she perks up, if she does then water her properly like normal.

Hard to say from 1 pic but might be overwatering or lack of airflow. Also check temp and humidity. Should be around 23-25c and 70 humi