I would not let the fact that it's a family member affect my decision. Why should I be more nice to someone than I would be to someone else just because I happen to share some of their DNA? (Of course, in many cases family members do things for you and help you out--especially your parents--and that'd make a difference, but no more than a friend helping you.)
In most cases I would not, but if I have a chance to betray someone like Saddam, whether he's my dad, brother, cousin, uncle, third-cousin's ex-college roommate's barber, or just a person I don't know, for 25 million bucks, hell yeah. Hell, I'd pay someone to do it. (Not that I'd ever have to.)
Edit: I voted the first option, because I read it as if I'm willing to in certain situations (see above), not that every family member of mine is worth less than $25 million.