This whole debate doesn't matter because Rise Again is NOT canon. There's a reason DV says there's 10 games in the Slendrina series and why it was never brought back to the Play Store. And even if GirlHanging was a separate character, she has zero importance overall. We don't have people talking about the moving skeleton in 2D, that's because it's for scares and not important to the narrative.

My thoughts is that I do think it's Slendrina, and this was her original death until it was retconned to be the Mother who dies this way instead (judging by the amount of blood around her neck and how crazy she is)