In the movie "Annie," how does Annie escape the orphanage?

In the movie "Annie," Annie is an orphan who is selected to spend a week with millionaire Oliver Warbucks. Mr. Warbucks ends up taking a liking to Annie and soon adopts her, rescuing her from the miserable life at the orphanage she was living in.

Grace Farrell, Mr. Warbucks' secretary, discovers Annie and is the person who eventually convinces the wealthy munitions industrialist to adopt her. Mr. Warbucks is known, in the beginning, for his cold-hearted nature, and he initially objects to the time Annie is selected to spend at his home, even though this is intended to better his public image.