Sugar water helps them get some energy, not sure how it works but adding it to a sick birds water can help them get more alert.
if you can you should quarantine her and give her food and water watch to make sure she’s drinking, eating, and pooping. If she’s not drinking dip her beak in and see...
There probably isn’t mold in the food unless it’s damp, have you checked her vent? just double checking, If she’s really lethargic and you can’t get her to eat try giving some sugar water.