Hamsters drink on average around 10-20 ml of water a day (2 to 4 teaspoons worth). Most hamsters regulate their own water intake, and drink when thirsty. Leave the water bottle in easy reach and make sure that the dripper spout is working. When she's thirsty, she will drink from it. If she doesn't but is lively and well, it could be she is getting fluid in other ways, such as eating fresh fruit and vegetables.