I can kind of see her point about housewife roles. But I would think it is pragmatism on the part of casting directors and not racism that keeps her away from those roles. Like it or not, there are not that many young black actors, at least not grade school aged. On the other hand there are tons of young white actors. I'm sure that may be classified as racism but the director doesn't make the situation he deals with what he is given. Not to mention if they wanted realism in finding kids who it is reasonable to be hers, you are limiting the talent pool even more by looking for children of mixed descent.
Yeah, it's ironic listening to actors complain about these things. Acting is the one field where it's absolutely necessary to discriminate in hiring. There aren't too many other fields that require an employee to "look" the part. It's the one career where they're hired not only on ability, but also on whether they're male or female, or they look a particular ethnic background, or they're just more attractive than most other people.
They grow successful based on appearances, and then when they're successful, they complain that Hollywood is based on appearances.