Her crop is probably blocked. Dont know if you know about the crop but I'll explain just in case. The crop is a storage bag on thier neck which is the first place food goes when they eat. Its a muscle and slowly contracts squeezing the food into the next part of the digestive system. A normal, full crop should feel a little like a stress ball. Sometimes softer if they have drank a lot, sometimes harder if they eat a lot of whole seeds or something. Sometimes it gets blocked for one reason or another and then they just keep eating and drinking but the crop isnt emptying. Thats why it feels like a balloon.
Try massaging her crop to help break up the blockage. Dont worry, she may not like it but this wont hurt her a bit. While you are at it, take a whif of her breath (gross i know) and see if it smells off. If it does let us know on here and i can tell you how to treat. If you can, separate her into a cage and give her no food or water overnight after her masage and see if it starts emptying on its own. If it does great! She can go back to doing her chicken thing. If it stays full overnight she will need more masaging and fluids to help soften the blockage.