She would always tell on Jem and Scout. But later for Jem to find out, Mrs. Dubose was only like this because she was sick. Later when Mrs. Dubose died, Jem learned more about her. She was very courageous and hard working.
In fact, ravens will eat just about anything, including the occasional pickings from garbage cans for the city-dwelling ravens. Their usual diet contains insects, seeds, carrion (meat from the carcasses of animals killed by predators), the eggs and nestlings of other birds, and frogs.
1 In winter, young ravens finding a carcass will call other ravens to the prize. They apparently do this to overwhelm the local territory owners by force of numbers to gain access to the food.  Common Ravens are smart, which makes them dangerous predators.