Of their family members isn't very normal. Of someone else is normal. Personally, I hate Facebook and I wouldn't wank to a picture on it unless you paid me. I'd just get a regular, non-Facebook picture. Or better yet, just not at all. Am I rambling? I think I am.
Not my thing, a few of my sisters friends are facebook friends that I would bang. I have a second cousin that I would totally fuck, but I've only met her like twice.
But immediate family, no way, just thinkin about it grosses me out.
Masturbation while thinking of family members is totally normal.
If u cant think about sliding it into mommy or sister while u wank then u shouldn't bother getting horny.