Cecetropes usually are smaller, shiny, and mushy, but not too liquidy. Most of the time they are in grapelike clumps, but if one was left behind then that could explain what you saw. Did she get into anything? Has she been on any antibiotics? Anything new?
The thing that does worry me is that you have noticed she hasn’t pooped and she a bit more low-key. With rabbits, I am always inclinced to say it’s better safe than sorry since they can hide illness so well, and to the point it’s too late. So I would check with a vet if you think she could be fighting an infection. Otherwise watch closely to make sure she poops soon. Also, listen to her stomach. Can you hear a light gurgling? It should gurgle every five to 10 seconds. A healthy gi tract should always be on the move, but if it’s very loud, like you can hear it without putting your ear to her stomach, then that can also mean digestive issues.
The fact that she is running around and binkying is a good sign, but just keep an eye on that litterbox, and how much she is sneezing. (it’s normal for bunnies to sneeze a little bit every once in awhile. Sometimes hay dust can do that or something else they got into)