I'm sorry to hear that she's still not eating well. I know that when my RB Pepper was constipated the first time he stopped eating and lost a lot of weight. This is when I used to free feed so I didn't even notice that he wasn't eating right away. I'd also ask your vet about possibly giving her vitamin B-12 shots. This helped my Ziggy get her appetite back when she was very sick last summer with mild pancreatitis. Lots of prayers and positive thoughts are going out to Miss Marbles.