im 16 and my step mom was just diagnosed with breast cancer....

My heart goes out to you and your family. It sounds odd, but in addition to being helpful, try to treat her the same way you always did.  Try to make her laugh and just be there for her.  If she is not too tired, let her know what is going on in your life--the things that you would want her to know if she didn't have cancer.  I valued the friends who asked if I needed help and if I didn't, just treated me normally.  Be strong and try not to freak out too often.  That said, there is nothing wrong with a good cry.  Is there another person in whom you can confide your fears and concerns?  While this board is good, there is nothing like a good friend or trusted advisor.  The hospital where I was treated had counselors for patients and families and perhaps you could ask if the place where your stepmother is being treated has a similar service.  It didn't cost anything extra.  Good luck.

Sue

PS You don't need to take on their roles.  Just find a role with which you are comfortable.  Big sister that helps with bedtime, baths and meals is a valued role too. 

I understand what a difficult position you are in.  When I was 16 my mother was very ill (not bc related) and I had to step up to the plate and keep the house running. You are correct your friends have no idea what you are going through no matter how many times you try to explain. You feel caught between caring for the family and wanting to be "normal" again.  Don't forget to take care of yourself and do those things that young adults like to do, it will keep your mind healthy for you and your family.  I am impressed with your maturity, your step mom is lucky to have a daughter like you.  I too, am blessed with a step daughter, she was a great big help to me last year when I went through chemo.  She lives across the street from me, but she sent me cards every week just to keep my spirits up, she made a list of everything she could cook and if I needed a meal, all I had to do was call her and she gave me journaling books so I could write down my thoughts.  I am sure your step mom will feel better knowing that you are caring for the little ones when you are able.  I just wanted you to know about the hair thing.  I could not imagine myself without it, I loved my hair, it was a big shock to me to have it fall out.  I realized that the chemo was doing its job, killing all the fast growing cells. I didn't lose it all, but I did look like Beetle Juice for a while.  It started to grow back quickly, and 8 months later my hair is long enough to style, alot curlier and a couple different shades of gray.  I like the new me.  Please PM if you need anyone else to talk with, you are not alone.