I think that one observation that can be made between the book and the film versions of The Help is that the endings in both are similar, but different. While both conclusions focus on Aibileen, the emphasis in each ending is a bit different. In the book, Aibileen is shown to be more focused on what she will do once she is dismissed from her job as a member of "the help." She will take up the column in the newspaper that Skeeter gave her. In addition, there is a greater sense of skepticism and fear that she possesses about starting new at such a late stage in life. Aibileen is released into the world of freedom and choice, but reflects a bit of fear and apprehension regarding this new reality.
This is not seen in the film. The ending in the film is one in which the "Miss Myrna" job is never offered to her. Aibileen makes no mention to the audience or to her employers that she will be taking such a job. At the same time, the ending of Aibileen walking away from Mae Mobley and into a world of freedom and choice is shown to be much more positive. In the voice over narration, Aibileen does not reflect any fear of the future. She does not indicate that her age and the concept of "starting over" might be challenging in any way. She walks on an open road of freedom, convinced of its certainty and opportunity. The note of reflection and reticence about this entity is not shown in the film as it is depicted in the book, and can be observed when seeing both side by side.