one way to improve her drinking habits would be to get a big bowl/container made of clay/pottery with fresh water, none of that plastic crap. Stainless steel could improve it also, you have to test it.

Better option would be an indoor "pond" or an aquarium with plants and some fish in it. They love to drink there.

I made a small pond just outside the house and the cats love to drink there. They drink a lot more than before. It has plants, fish, frogs and water snails. That's it.