Glucosamine is good, but takes a while to start working. You might try a Feliway Safe Space plug-in - it's "kitty incense" that humans can't really smell (unless I'm right on top of it, then it's a very faint cedar-coconut smell) that has a calming effect. The drinking fountain's a great idea! Be sure to get a mat to put under it, though, if she's a splasher.

Love, Columbine