I don't have a black sheep sibling but my husband sure does. I honestly wonder all the time how he is related to one of his sisters. She is unlike anyone in the family. It's crazy and slightly embarrassing!
Definitely a yes. My husband and I are both the "good" children in our families. That means we get significantly less attention - while this is often a good thing, we've found that the squeaky wheel gets the grease, along with the financial support. We in no way need our parents' money (because, unlike our siblings, we have made good decisions), but it kills us to see our parents throw money at our siblings when they consistently make poor decisions.
Re: Sibling poll