I'll definitely keep an eye on her feet, but right now they look dry/cracked. I'm assuming it's from the hard surface they were on. The fleece should be more comfortable now, so hopefully that'll get better quickly. If needed, I'll post a picture. I'll also check out her cagemate's feet.
I'm glad it was ruled out, too. She peed on the paper towels that were lining her travel carrier yesterday, and the vet said that looked completely normal. They cleaned the yellow stains with some sort of animal shampoo yesterday and today the stains are less visible. The vet also suggested wiping the area with baby wipes if I could.
I'll make sure to watch their droppings. They look normal so far, but I'll monitor. Is there a specific way I should clean their waterer out when I swap their drink?