A little toast or a bit of bagel might do the same thing and might be more appealing. Maybe even a Cheerio.
The other question is how bad is it? Is it pellets that have a shape but are so soft that they get crushed by little feet or stick to the cage wire? Is there mucus? Or is it so bad that you can shake her up and aim her at someone you don't like.
In the event of the first one, this happens about once or twice a year to Max. It usually goes away after 3-5 days. I think it might be change of season or extra stress. I give the bottles an extreme wash, cut back on treats, and give plenty of hay, and it usually clears up. And some chins are more prone to this than others. Some have sensitive tummies I guess.
The other two, I'd try to get a fecal flow test. Honestly, I had one done once when there was mucus, and there was nothing unusual, but it gave me piece of mind.
I don't know what to say about the weight loss. Except for Maureen, my chins are hungry, hungry hippos.
Good luck. Hopefully things will clear up.