I have had my 11 week old great dane puppy for two weeks, and she has been reliably going outside, with no indoor accidents, for 5 days now. First, IMO, the object is not to catch her and stop her from an "accident," it is to prevent an accident from happening. That means you take pup out after naps, after eating, after playing, and whenever she seems to even think that she needs to go. Then you reward like crazy, telling her she is the smartest, best pup in the universe. I have a great advantage in that I can be with her 24/7 (I'm a teacher and off during the summer) and I got my berner during my spring break years ago, and he was totally housebroken 10 days later when I had to return to work. I find the constant attention, bonding, rewarding and PREVENTING accidents before they happen patterns the desired behaviors and eliminates any confusion in the pup. The more the undesired behavior happens, the harder it will be to unlearn and reteach. It's a LOT of work the first weeks (alot of fun, too) but it's really alot less work than half hearted attempts at training that go on endlessly. If she sees the pup messing in the house, it means she was there to begin with, and needs to be more pro-active and aware of the pup's needs almost before the pup is. Also, she needs to clean accidents completely with Nature's Miracle or another natural enzyme product to eliminate the smell, to prevent a repeat offense in the same spot. Good luck to her.....
Jane Hudson Valley of NYS