We do not feel the mother took our warning to heart, because she said "that I should just get over the fact that our son separated my ribs causing breathing problems for around 45 days".
Well, that's a horrible thing to say to someone in your position. Get over a physical assault which caused you breathing problems, thus endangering your life. That's not something you need to "get over" in anyone elses time other than yours...and she should be a little more compassionate of your situation...which it sounds like she isn't.
Even as a Christian that trauma happened a year ago, this was around the time the dating started secretly and I still have some problems with my ribs on the right side. That makes it hard for me personally to just "get over it".
I think it was a terrible thing to say to you. You will move on from that in your own time, and heal in your own time. It's not for anyone else to say that, and I find people who do to be so ignorant and stupid. I know I said it myself when I was much younger and stupid and ignorant. Hopefully some day she will also come to realize it isn't an effective strategy for helping someone in pain, nor is it showing compassion in any way when that is what is needed.