There's a great possibility that she does have Indian lineage considering her birth in Oklahoma.
Not all people of Native American ancestry are red faces and dark hair. There are a large number of white people throughout the Midwest who have mixed genetics and are non registered.
Her story is believable.
i don't think her (warren) story is believable (in its whole, it's believable that she thought she had cherokee ancestry), and i do think that it reflects on her character that she tried to claim herself as native american, presumably in order to gain favorable placement for employment.
at the same time, it annoys me that the media swallowed the cherokee mafia's assertion that your ancestors were other listed on the rolls and then you're a cherokee, or they weren't, and then you're not.