She might have a bit of bumble foot/infection in that back toe, but I doubt that is causing her to wobble so (perhaps, but she doesn't seem to be picking up the foot as if it is sore). She might have injured something jumping down from the high roost. Chickens won't show injury or illness if they can help it as it shows weakness, so it can be hard to guess what might be the underlying cause.
Good news is she is eating, drinking, and wanting to move around, but something is definitely going on with this little lady. I would isolate her so she has a warm little spot with food and water close by. Continue to clean the back toe out with Vetricyn and watch it to make sure it doesn't grow into full fledged bumble foot. I read that you can apply Tea Tree oil, vaseline, then bandage to treat moderate bumblefoot, checking and re-bandaging every couple of days.
If it is a leg injury, with no broken bones, I can say I had a rooster than was fine one day, and then limped heavily the next. Eating, drinking, but had a severe limp. I couldn't feel any broken bone, and the leg responded properly with the foot flexing with touch. I found some old weed eater twine in an odd place that had been unraveled where it has been sitting elsewhere the previous day, and I think he got caught up in it and injured his leg trying to pull out. I gave him some TLC for a couple of days so the rest of the flock wouldn't make him have to use his leg a lot, and he improved. In a couple of weeks he was walking normally again.
A few days of watching her should help sort out if she is sick, injured, or bumblefoot.
LofMc
