DH is scheduled for his 2nd Lithotripsy tomorrow. This is after two surgeries to remove two big (think golf balls) stones last year, as well as one lithotripsy for this last stone that wasn't 100% effective. Lithotripsy is a 'shock-wave' therapy to attempt to break the stone into smaller pieces that can be passed (hopefully without pain).
The doctor gave him the option of doing nothing, but if the stone decides to move, he will be in major pain. And it's too big to pass. So, he elected the 2nd try at lithotripsy.
All the stone fragments that have been removed are Calcium-Oxalate stones. The doctor has not recommended that he limit his calcium, but has recommended a low oxalate diet. For us that means cutting out beets, rhubarb, chocolate, nuts and black tea. There are other high oxalate foods, but we don't normally eat them.
There are other types of stones besides calcium-oxalate. But, the stone has to be removed to determine what kind it is. Calcium-oxalate is the most common.
I still don't completely understand all the complications that kidney stones can cause. But, after finding two large stones in the same kidney, the doctor ordered a kidney function test, to make sure the kidney was worth saving. Now that was scary. Fortunately, while the kidney was not working at 100%, it was worth saving, and the stones were removed.
So, after my long reply, my recommendation is that she find a urologist that she trusts, and follow the doctor's recommendations.
And, yes she should drinks lots of water. My DH aims for a gallon a day. In addition to any other drinks, like coffee.