I use a 1/4" cup measuring cup with a long handle. It's small enough to slip underneath. Lady also has no modesty so it's not a problem.
Cranberry Relief is a good cranberry supplement for dogs. You have to find out what her pH is first, though, so you don't mess up the balance and cause stones. Dogs should have a neutral pH of about 7.0. Less than 7.0 is too acidic and greater than 7.0 is too alkaline. Cranberry will lower urine pH so it should only be given if the pH is too high.