Zebra hen- problems with perching/balancing

[nelloyello11]

This morning, we woke to find that one of our zebra hens is having difficulty perching and balancing. She flies fine, is eating and drinking normally. Her droppings seem to have some excess urine in them, but all of our finches had some clover sprouts yesterday, so that may be the cause of that. Her vent area does look a little weird, as if it has been plucked a little, it might be a little wet, but there are no crusted droppings around the vent. When she perches, she seems to sort of slip off the branch, and when she is on the floor, or in the seed dish, she seems to lose her balance when the leans forward to grab a seed. She is slightly puffy sometimes, but not constantly. She doesn't seem to have trouble with her wings or legs, and hops around normally. She is vocal as usual.

The only change I've made, is that I removed the wire divider between the flight she shares with her sister, and the one with their father, so the three are all in the larger space together now. They had previously been housed together, along with the mother, who died several months ago. Since it was a wire divider, they were all mostly exposed to each other; both other birds are fine.

I placed a heat lamp over one perch, but she doesn't seem very interested in using it. I also placed an extra seed dish on the floor, as well as a small dish of water, with calcium plus, in case it might be egg binding. In their regular water bottles, I added some thrive. She has drank from both, and bathed.

Is it popssible she might just be tired, if she didn't sleep well due to the new arrangements? Or more likely something else?
Any help is appreciated!