Hello, I am Dr. Peter and would like to help. In response to your question, when a dog drinks more than usual, it is an indication of either an infection, kidney or liver disease, hormonal disorders (diabetes) and even cancer. The urine leakage could be directly related to drinking more or she could have a weak urethral sphincter. If this was my case in the clinic, after a thorough physical exam I would request to see:
1- Chemistry profile, CBC, and urinalysis: These tests will tell me about her kidneys, liver, infections, glucose (diabetes), etc.
2- Xrays: If the blood test are normal, we proceed with xrays to look for other possibilities like tumors, stones, etc.
I would advise you to consider having your vet take a look at her and do the above tests. Once they have the results they will be able to explain and treat her symptoms.
Hope the above helps, if you have additional questions I will be glad to answer them.