Friends, I had previously discounted the possibility that this could be Ms Stanton----------------

----------------because the forearms didn't look thick enough.
However! Looking again at the photograph we have of Ms Stanton, I noticed that the upper arms are very thick but the forearms not nearly so much------------
Something else worth bearing in mind:
Mr Lovelady,
before ever seeing the Altgens photograph, only named one other person there on the steps:
"When the Pres. came by
Bill Shelley and I was standing on the steps..." (Affidavit, 11/22/63).
However, we know that one thing he was to notice in the Altgens photograph was the second-floor lady shielding her eyes. This must have triggered his recollection and prompted him to mention Ms Stanton as well as Mr Shelley in subsequent statements about who had been there with him / next to him on the steps. Because that was exactly what the Altgens photograph was showing him.
Possibly Significant Sidenote! Mr Lovelady
mistakenly thinks that the Altgens photograph is showing him way over by the west wall of the entranceway, when we know he is actually near the center railing!
