Not sure with all that is going on with her if it may be ascites or not. Usually it feels waterballoon like. Most birds that have ascites do not lay anymore, so if she was recently laying that may not be the issue. If she is molting, that can sometimes make them feel pretty bad too, and they don't lay during molt. If it's a molt issue then I would just keep an eye on her and up her protein a bit, offer some cooked or scrambled egg, a bit of canned tuna, even sometimes a bit of canned cat food will tempt them (I'm not a fan of that particularly, but some find it helpful if they aren't eating well). I would not do the sugar and cheese, too much fat/carbs and dairy can cause digestive upset if over done. I don't know what a vet might charge for either an exam or draining her, I would call around to see if you have one that will see a chicken and ask what they might charge, most of the time they can give you an office visit amount at least and you can discuss treatment options if needed then, many are reluctant to quote treatment prices without knowing what they are dealing with. If it's molt, then time will be what she needs. Many birds go through molt with no real issues, but some of them sometimes can feel awful and seem down. Pictures of your bird might be helpful, to see how she looks, particularly the abdomen.