After the divorce, there is no listing for Rose remarrying under the name Farrell or Putman in Colorado thru 1939. I checked the Federal census(1920)for listings in Colorado for Rose and her son. And did not locate anything that I thought close. My assumption is that she moved. But, that is just what I am thinking.
I am wondering if you followed up on her son's death in Vancouver,BC? Maybe there were some children? Obit? That might give you some leads
Good Hunting