Inconsiderate People

I am a pretty out spoken person.  I have recently been pissed off by an inconsiderate person who lives her life in a bubble of selfishness and shallowness.  She is also delicate like thin cheep glass, and is easily hurt.  So my problem is that I really want to tell her how I feel.  But I am terrified that it will scar her for life.  I am trying to give it some time so I can cool off a bit.  I want to be and adult about it, in the same breath I want her to know that I am not going to let her treat me like she treats other people.  I want to be taste full but I am not going to lie I am pretty angry with her.