Hello and welcome to BYC!
What is her age?
Water blisters on the legs and in other areas is exactly how my aunts heart disease (and kidney failure) progressed.. Some humans get dyalisis to slow the progression. This possibility really only came to me because of her breed.
Separation is lonely.. and reintegration can be brutal.
What is your feed routine, including treats and supplements? Questions to see if there is anything that *may* be suggested as helpful to managing conditions.
Does she roost? Does her abdomen feel squishy? How does the skin look below the vent? How bright is her comb?
I'm trying to think of any way a chicken could get a blister.. I've not seen it YET.. but do discover new things daily.. Hoping with pics you may get better answers than mine!