I was trying not to make this a second guessing discussion about the play itself, since it's a judgement call and you HTBT. I felt, and still do, that the judgement that F1 was attempting a play was a stretch and so was curious what physical cues the blues look for in deciding that a play is being made. I didn't think that standing with your feet side by side and holding the ball up in front of your shoulder (sort of like you'd hold a drink if you were about to sip it while standing up) was enough to get a "making a play" call, but at least one blue felt differently.
That said, to Bretman's questions:
Where was the runner at third actually standing when the batter-runner touched first base?
I thought she had gone back to stand on 3B. It's possible she had not quite gotten there. I was running the scoreboard,keeping the book, and paying more attention to the BR (since I thought she might take off for 2B) and so was not fully focused on where R1 was when BR reached 1B. From the followup discussion I had with the ump, I have to assume he felt she had gone back to 3B, otherwise the discussion wouldn't have been about F1 making a play.
If she was off the bag, then she would have every right to immediately advance toward home
Agree, emphasis on immediately (see below)
What was the timing between the time the LBR kicked in and R1 started advancing?
Yes, the pitcher did make an actual "play" when she started to exit the circle to make the underhand toss home. Before that point, if R1 was off the bag, did she remain standing still before heading home and before the pitcher started her play? If so, then she would be out. You'd have to determine which came first- the runner's extended pause or the pitcher's "play" on her.
BR had reached first base, and R1 was not standing still unless she was on 3B. She was either there or moving back to 3B when her coach hollered at her to go. Again, based on how the ump responded to my "why no LBR violation?" question, I have to assume she was either on 3B or headed towards it, not standing still, because F1 had the ball for more than a second or two before R1 took off. It was almost like a very delayed steal - everyone had relaxed thinking nothing was going to happen and then bang. Give 'em credit, it was a heads-up play.