Keep fresh water available in a quiet, out of the way place, but also don't worry about not seeing her drink. I haven't seen Midas drink since we switched. I have dogs that he shares bowls with, so I wouldn't know if he was drinking unless I saw him. Unless she has some sort of illness, I don't think there is cause for concern.
Does she look otherwise healthy? No sunken eyes or anything?
There are ways to check for dehydration in cats: the first is the skin test, where you gently pull the skin on the back of the neck up as if you were scruffing (though no lifting is happening!). Watch how quickly the skin lies flat again. Hydrated cats should have skin that flattens quickly, whereas dehydrated cats will have skin that takes longer to go flat.
The second, a little more invasive, though no more than brushing their teeth, involves lifting your cat's upper lip, and then pressing your finger flat against the gums. When you remove your finger there should be a white spot. In normal cats, the gum will recolor in 1-2 seconds. Dehydrated cats will take longer. Looking at the gums is good point for checking overall health anyway!