Ok, here I go with my stab at this.
First, did the runner complete a legal tag-up? Was she standing on 2nd base when the ball was first touched by the RF? Kind of sounds like no if she was retreating to the bag already but since there is no mention of an appeal, she might have tagged-up legally.
But let's assume that she did tag-up legally. Cannot score a SF because the runner did not score.
Any attempt to advance a base when the ball is in play
unaided by a safe hit, putout, error, force out, fielder's choice, illegal pitch, base on balls, hit batter, wildpitch, passed ball, interference or obstruction is, by definition, a Stolen Base unless the defense showed "Indifference", then it would be a Fielder's Choice.
Now, I do not have access to my scoring references here at work so if I am way off-base (pun intended) here, then tag me OUT.