To round off this part of the story, I should describe my paternal grandfather. But I realise that I know practically nothing about him at this stage of his life - about 1910-1920.
His name was Selwyn, poor chap, and he was about 20 at the turn of the century. He was educated at Glenalmond College in Perthshire (his mother was Scottish, his father English, and so the elder son went to Winchester (I think) and the younger to Glenalmond) and then Oxford. He became an electrical engineer.
During the course of the Great War he became a major, and that became the name he was called by for the rest of his life. One can hardly blame him; Selwyn does not trip off the tongue.
At the time of my grandparents' separation, a divorce was not that easy to obtain. There had to be a guilty and an innocent party, usually of adultery. Sometimes, the husband offered to 'provide the evidence' so as not to blacken his wife's name by an accusation of unfaithfulness, but there had to be no hint of collusion, nor an indication of guilt on both sides as the one cancelled out the other and a divorce was not granted.
However, in this case, I imagine that it was a clear case as Helen had run away with her lover and the Major divorced Helen. She went on to marry Colonel Wake and had two more sons, William and John. She was, of course, cut off from her considerable inheritance by her horrified parents and so, when the Colonel became ill with cancer and died, she was left very poor - presumably the Colonel didn't have much money himself.
The Major was a gentleman and could not see his former wife destitute. He and Helen had kept in touch for their son's sake - how much affection was still there I don't know, but forgiveness there must have been. They remarried and he brought up her sons as his own.