Broken rib a bad sign?

First of all, we are so grateful for all of you brave women and men who post here and for all the helpful information you share. You've helped us more than you know, and we keep you all in our prayers. I posted to the Friends, Family & Caregivers thread but haven't received a response. I hope it's okay if I post here too. Please let me know if it's not appropriate and I will delete. My husband and I are longtime readers of the board but this is my first post.

My husband's exwife (my 12 yo stepdaughter's mom) was diagnosed in July 2014 with Stage III breast cancer, many positive lymph nodes involved. Several months later, she had a mastectomy (one side) and chemo. We think her chemo ended in Jan/Feb 2015. She declined the last two recommended rounds of chemo and she declined radiation. We're not sure about hormone therapy, but we're guessing she declined that too. The great news is that she's very active physically and has been healthy since treatment. We don't know what kind of follow up care she's getting, but she's told my husband that she's doing well.

I'm afraid that's all we know. She doesn't share much info about her cancer with my husband, and he respects her boundaries. Her health issues are hers to share or not share. But she did just call to tell him that she broke a rib a few days ago when a friend gave her a big hug. She's in pain. She hasn't gone to her doctor, just a chiropractor. He said he didn't want to work on the area because the rib was broken.

My husband doesn't pry. He listens to whatever she wants to share, and he leaves it at that. But then he and I try to learn as much as we can through research. We are aware that bone density can be affected by chemo ... especially since she most likely declined hormone therapy? We also read that sometimes broken/sore ribs can be linked to metastasis.

Given her natural approach to health, we're not sure if she's going to see her oncologist about the broken rib. I guess we're just trying to get as much info as we can to make sure we're here to support her and their daughter, who lives with her dad and me half the time. For the first time since her diagnosis, my husband is wondering if he should follow up with her to see if she's going to meet with her oncologist. He's torn about that.

In your experience, is a broken rib in this situation a big cause for concern? Especially since she didn't have a fall or another injury? She said her friend (who is a big guy) gave her a hug and she felt a 'pop' and was instantly in pain.

Do you have any advice for my husband on how to handle his concerns? Of course his exwife's treatment decisions are hers to make, and hers alone, and my husband would never interfere. But it does get complicated and everyone worries because of their daughter.

Thank you in advance for your help - thank you all for being here! Blessings.