Anything is possible but the long held theory is that Loretta Martin is Yoko, and it's John who said that one of the reasons he loved Yoko is that she looked like a man - in that she wasn't excessively 'feminine' in that stereotypical show-biz manner. Paul used to sing "Get back" to Yoko whenever she showed up in the recording studio. But Paul, who wrote the song always said that the lyrics were pretty much nonsense that rhymed that they came up with while they were jamming on the song (which they didn't write, it's pretty much an old Big Bill Broonzy tune.) And it had other lyric lines, but they were deemed offensive - or might be construed that way - so it's possible that it was just a last minute deal of finding words that rhymed more than they made sense.
