I had an early stage breast cancer. It was found only because my friend nagged me every day to resch. my mammi appt. I kept saying we were to busy at work & I would do it in a few months. (My fist lump was removed when I was only 22) I think the pink ribbons do remind us and that's a good thing. We get busy and forget to take care of ourselves even after we've been there before. It's been over 10 years and I still wait for that "all clear you can get dressed".
Ask your sister what she thinks about the pink ribbon things.
I hope you are not putting off your mammi's and have talked to your Dr. about your sisters conditions.