Are you outside watching them while they're outside doing their business? Just wondering, since you say she's hiding when she poops inside the house. Sometimes dogs don't associate the scolding with the fact that they peed/pooed inside. But just that they did it in general, so they try to hide from their owners when they need to go. It doesn't necessarily have to be because you've been too hard on her or anything. Some dogs are just more soft than others
Maybe you could try to hide somewhere while she's outside, so she can't see you but you can see her... and be ready to throw a party if she poops xD

If you don't think that's the problem. Then I suggest you keep trying to stay outside with her and perhaps have her on a leash. Don't walk around and let her explore. Just stay in the same spot and wait until she poops. If there is already a smell of pee/poop present in the location, she'll be more inclined to go.
Same goes for inside. Make sure the areas she uses are extra well cleaned with something that completely gets rid of the smell. Perhaps some special kind of soap from a pet store, or something, would do the trick? I can't recommend you any specific brand tho', since I don't live in the states, so I don't know what kinds you have over there

I definitely also strongly recommend a feeding schedule
Good luck!