Effects of Being a Pacifist

Everyone has met that one person who over all is just, pacific and plainly quiet, in their lives but has anyone stop to think what they go through to be that way? Well, my sister has this type of personality and suffers greatly because even though shes got something to say she keeps it in, she is a follower not a leader, her friends treat her wrong and unjust and she blames herself for being the way she is and many more qualities that represent such people who are enclosed within themselves and all they intend to do is satisfy others before being content with themselves. My sister attends middle school right now and is in the 6th grade, and comes most of the school days nagging about how her so-called "friends" treat her, and how she doesnt know how to answer back saying what she feels or at least defending herself. She has always been a shy and quiet person with the people she meets and with her peers, anyone of her same age or older. She always is intimidated by others and closes herself, permitting her to lower her self-esteem. I suggest that if anyone is like this, has a personality such as the one my sister has or any smilarity please beware of those individuals out there that don't know you and bring you down without you having rare possibilities of defending yourself. Do not be afraid of who you are and expressing you sentiments straight up. Any suggestions on how to deal with a family member, friend, or even oneslf who has issues similar to this..?