SHE MET HIM ONLINE

She met him online. MY BABY SISTER (yes i know she is technically older than me, but in life years she is infinitely younger than I) met some guy on the internet and FUCKED HIM. So i like to consider myself a very sexually enlightened girl, and I have posted about how I don't judge peoples sexual choices. Now I find myself in the awkward place of judging my sisters choices. I like to think that because she is my sister I have every right to judge and/or question her, but in all reality my own choices about sex have not gotten me membership in MENSA. I love my sister dearly, I do, but she does not always make the best decisions, and she also has special circumstances that make her decisions about sex particularly worrisome. She has never really been in a relationship, never had a serious boyfriend and now she decides to hand over her V-Card to some loser ( I have chosen to view him as a loser because he has royally pissed me off) like its a stick of bubble gum. Now i shall list the sins against him:
1. I have my doubts about guys who pick up chicks on the internet, I mean what is wrong with them that they cannot pick up girls at a bar like a normal guy? (not a freaking word Katie you hear me?)
2. My mother says he looks like a skinhead. That one speaks for itself.
3. He is old... ok so hes like 27 but thats too old for her.
4. He has a kid. Now I know that not everyone who has a kid out of wedlock is a loser, and I am not usually so judgmental, but this is my sister we are talking about, I don't want her to be with some asshole who knocked up his girlfriend. Not to mention my sister couldn't keep a fern alive for more than a week.. and now shes gonna be Stepmommy Dearest? I don't think so.

He could be a perfectly nice guy, who genuinely cares for her. He could also be the scum of the earth, I just don't know. All i do know ishe is going to get his face smashed in if he hurts her.
My question is, am i overreacting? Am I being crazy? And if I'm not, what the fuck am I supposed to do?