Any change in the amount she is drinking? Was she outside prior to this weird walking behavior ("ataxia")? Any plants or medications she might have gotten into? Is she otherwise acting normally--responsive to your voice, alert, etc?
She has gone out side, but stayed on the deck. She is 80% responsive to my voice. Usually she wakes me up in the morning with nonstop meowing at my door to be fed, but not this morning. I had to go find her, pick her up and take her to her food dish. Once there she ate all of her food and drank water. I haven't noticed if the amount of water she has drank is less than usual.