OT: recommendation for breast cancer site

My SIL just received a breast cancer diagnosis...she's widowed with no children, so my wife and I will be her support group on her journey. I've been trying to get up to speed on breast cancer the past 24 hours and looking for an internet site/community that is helpful as HW was to me when I was diagnosed. Anyone have any recommendations?

In the early innings I have found some sites to be helpful (breastcancer.org, inspire.com), but any guidance would be very much appreciated.

That surprised me as well, since it was the first place I looked. I think we're fortunate here in the House of the Prostate to have such a robust community...