Answer:
 glasses
 glasses
Explanation:
The ounce part does not matter because you are trying to figure out how many glasses of water she drinks in a hour.
 g =
g = 
 h
h
divide by 4 to get the hour fraction easy to work with
 g =
g = 
 h
h
times by three to get one hour
 g =
g = 
 h
h
your answer is 0.5 glasses or 
 glasses
 glasses