Am I reading this incorrectly/overreacting?

[emek]

One if my sister in laws only hugs my fiancé, but never me.

Personally, I think it's extremely rude and immature. I've been in the family for 7 years. I am 27, she is 30. She has always been very immature, using drugs, going from job to job, threatening to kill herself for attention (she only does it when her mother travels up north to visit her other sister - she purely does it for attention). One time she even attacked her mother with a knife. Now she doesn't work and blushes off her parents. She can drive but makes her 67 year old mother drive her everywhere. She is lazy, doesn't clean or cook or contribute. Any money she does have she spends on her tattoos and piercings (she has almost entire body covered in tattoos and around 30 piercings). She is the youngest of 5.

The whole family dislikes her (aside from her mother) my fiancé said he can't even look at her because she disgusts him so much. No one is openly rude to her face, but she can probably tell. I have never been rude to her and I try talking to her, she doesn't act like she hates me, but I know she says stuff about me behind my back. 

I don't care about her hugging me, I just think it's rude to single me out. She has hugged me a few times over the years, but now she's purposely singling me out.

She's doing it on purpose, isn't she? Or am I overreacting?

I realize some of what I wrote makes me sound bad, but I'm trying to paint a picture for you so I can get some insight. Maybe I am missing something? She's not even close to my fiancé. Also, I get really well with the rest of the family.

[lorimar]

Are you reading it wrong? Maybe not. Are you overreacting? Maybe so.

Just because a person does something crappy doesn't mean you have to react to it. When she hugs your fiance, throw your arms open and say "me next!" If she refuses at that point, she will have to explain her reasoning.
Act rather than react. Do what you planned on doing regardless of what this dysfunctional person does. That's the best advice I've got for that one. Don't get your expectations too high, she's not gonna be your best friend, but that's okay. She's got her problems, and you have your fiance and the rest of your life.
Resist the urge to point out what she is doing. If this is one of those families that talks behind the person's back rather than confronting problems, let them do things the way they do them - in your house you can set your own rules of honesty and openness, but in their house, play by their rules if you can.

[bernd]

To me, it's obvious that you should ignore her antics, she is unstable and you shouldn't take her weirdness personally, she may be able to sense your contempt for her, maybe she knows you'd rather not hug her so she lets you have a pass, I have done that. You should really just let it go and save your concern for someone more significant.

[vemados]

way overreacting. i take it that this is your fiance's sister? do you actually want her to hug you? if the answer is yes, then you need to make friends with her. if the answer is no, you should be grateful...

[reid]

Well being the youngest and then you coming in she probably feels like shes being replaced so she does anything she can to get attention because shes jealous of you my advice just talk to her and make her feel important

[osryd]

Don't react to everything a person says or does. For instance, if she singles you out then just act and pretend that it doesn't bother you. If you react to it, then most likely she will continue to do it because she knows that it bothers you. Some people do things just for attention and to get a reaction out of you. Yes, in my opinion she is doing it on purpose but with you reacting to what she is saying and doing your overreacting to.