I totally understand your concerns but it is true what they told her - 9 out of 10 times it is nothing, just benign tissue.
But, of course, there are other issues that are important to know. For example, if she has family history of breast cancer (mom or sisters), she is definitely at a higher risk for having it as well. However, given the fact that it was found on mammogram, even if it is bad, it is very early and having surgery will get rid of the entire cancer area. What I am trying to say that even if it "bad", it is still ok because it was found early and is curative.
One of my nurses at work (with history of breast cancer in her mom and in her sister) had a spot biopsied which turned out to be early (very early) breast cancer. She opted to have both of her breasts removed (because of such heavy family history). There was actually cancer in the other breast too but too small to detect even with mammogram. So she is 100% fine, had breasts rebuilt and is doing great.
Your friend should be able to do a biopsy within the next 4 weeks. Hysterectomy should not interfere with getting it done after the first week or two.
Don't worry, chances are it is nothing!!
Sorry for such a long dragged out answer :)
Having family history of colon cancer does not put someone at higher risk of breast cancer. But colon cancer does run in families so that's good that she has been getting regular colonoscopies. If her colonoscopy was normal (without polyps), she really doesn't need to have colonoscopies every year, it is usually every 3-5 years.
Hysterectomy is a big surgery so I am not surprised she is still in the hospital. She will be in pain for a few weeks still. Anyone who has any kind of surgery is at risk of blood clots, its not just hysterectomy. The reason for this is that person who is having surgery is immobile during and after surgery and the blood is not moving as well. That puts them at risk for developing the blood clots. The longer the surgery, the higher the risk.