Trees I wouldn't be too worried by the age gap in that newspaper report. Journalism then was more of an art than a science. Say the reporter forgot to make a note of her age. There was no way of checking his story, no telephones etc. so what would he do, he would guess how old she was.
I think the time for something happening to Annie is Aug 1873 to Dec 1875 and I would say nearer the latter date. He could have been making a quick escape if he had done something to Annie, or she could have become fed up with his carrying on and left him.
avm Yes she becomes Ethel ( I think)