The Color Purple is Whoopi's. She owns, makes and elevates it. Maybe a little over-sentimental, but it's undeniably powerful.
That being said, the movie does contain some material that is not appropriate for kids. Racism and sexism are the film's main troubles, and Celie beats them all. There's semi.explicit sexual content, some foul language, horrific violence against women, smoking and drinking.
But the ending is, by all means, extremely moving. If your kids are mature enough, you should consider watching it with them and discussing issues of race, violence and respect for women.