Dogster.com says on its website that normally a healthy dog needs 1/2 to 1 oz. of water per pound of body weight so you could measure out her optimal limit for the day and see how much of that she drinks in a day. My Tibbe has small matching bowls that hold just about 10 liquid ounces and his water is changed twice daily. Some days there isn't much missing and other days, it's almost half gone when I wash and refill the bowl. He eats a mixture of canned food and kibble and his treats consist of moistened, refrigerated kibble so he gets some water in his food during the day.
How Much Water Should a Dog Drink a Day? | Dogster