BellaOnline Forums Family Siblings Need advice about my "stepsister"

Hello,

My dad was remarried about 7-8 years ago to a women who has 4 kids from a previous marriage. I never grew up with them or lived under the same roof. I only seen them whenever I would go and visit my dad. Sometimes that would be often, sometimes it would be once in a while. Always on the holidays though

Well my dad's new wife's oldest daughter always displayed a lack of personality around me and my dad/s side of the family, she was very seldom talkative and friendly, and when she was it would always appear to be very fake and phony to me and my dad's (her step-dad's) side of the family.

Well I just received confirmation from a very reliable source that she said the following words, "I can't stand anyone on my step-dad's side of the family." A friend of a friend was chatting with her on myspace and that is exactly what she wrote to him.
He forwarded it to me practically right away.
So another words after a good 3 or 4 years of suspecting that,
I pretty much got it from the horses mouth.

First, I'm trying to think of reasons why, and honestly can't think of any.

So every time there's a holiday function she greets my uncles, aunts, cousins, myself, and most importantly my grandma with hugs and smiles which has been extremely fake and phony all a long.

I personally do not feel like tolerating this and am feeling like I should confront her. I'm very protective of my family when it comes to things like this. I'm guessing that she will just lie anyways. I just want my family to know the truth so they don't keep wasting their time with her. I could show them what she typed but it was accidentally deleted so now I don't have that solid proof.

What can I do to convince my family that my suspicions were real and true, so they don't subject themselves as fools anymore by buying into to her phoniness? How do I do that without it backfiring on me and me turning out to be the bad guy because everybody just automatically looks at the pretty girl as the victim, and I'm a the male who is also older than her.
And how do I do all this without causing a rift or problems between my dad and his wife?

I don't care if she doesn't like me. Then I don't want her to come up to me smile and hug me if you she doesn't mean it.

But that's not as much of an issue as it is about my family.
It's my family, my blood, that she's pretending to like and being phony that bothers me, especially when it comes to my 85 year old grandma. I'm pretty sure they don't realize what's going on here, and are being taking as fools.
They always make attempts to treat her like family, holidays or not.
If she had a legitimate reason for not liking our family, then I wouldn't have a problem. Harmony, courtesy, and polite gestures, shouldn't be fake or phony. We don't expect her to be affectionate or overly affection, but she should be genuine and not play my family as fools. She has the nerve to ask my father for money. My father's wife convinced him to put her name on their car insurance even. She's taken advantage of him and the situation, meanwhile she doesn't like us. I will not accept that.
And I think I should speak out to protect my family, even if I have to be the bad guy.

You are acting like a little girl. This is not a major issue, you are going to run into fake people the rest of your life, and you should ignore them, just like you should ignore your step-sister. So you tell your family then what are they going to do? Tell her to stopping coming over, or stop hugging her, or stop talking to her, NO! nothing is going to happen, so you would be wasting your time. The truth is you are jealous of her.

I am very aware that fake people are going to be in and out of my life. The problem is that she is taking advantage of my family but at the same time saying that she doesn't like them.
They have done everything to make her feel like family. They have even helped her out. Some of them have help her out with her high school and college school work. When she moved into her first apartment, she hardly had any money for a mattress and furniture. We helped her with that too. I'm not asking her to bow down to my family and kiss their asses because we did those things simply because we wanted and we care.

Now please explain to me what the reasons are that I would be jealous of her?