Discrimination on the Flipside

Instead of an actual article or something of that nature I actually have to report an incidence that affects me personally...or rather my sister. My sister is 11 and goes to Meredith Middle School. For the most part it is a pretty diverse school for being in Iowa (granted it is in Des Moines). Anyways... She is 11 but she still understands the concept of discrimination, whether or not she understands the actual term. There is a group at her school called the "Sisters for Success" that gets the chance to go on field trips and do little fun projects as a group. It is sort of a club that recieves special priveleges if you are a member. My sister, naturally, wanted to join. Who wouldn't want to go on field trips? They turned her down because she was white. They told her that this was a group only for African American girls. Disappointed, she told me about it. I find this very interesting. I know that there is an understanding that groups should unite and band together to celebrate who they are, but she obviously wanted to join this group. From what she told me, it doesn't seem like they are actually doing this in the first place. They mostly just meet to be friendly, not necessarily to talk about race. I could just be bias (given that this did happen to my sister) but I feel like this is wrong. She is 11 and she does understand what is going on, but what are your thoughts on the subject? Is this type of thing a problem?

...also.. when we talked about this she said the most interesting/adorable thing she probably could have, "actually... I feel kinda bad for the boys....they don't have any sort of group for them."