[CecilOne]

In spite if my thinking you are married, I'll comment.
BR/R safe at 2nd, F4 benched, not sure of question.

If the question is whether the BR/R can advance, why not? You said nothing about calling dead ball or time, so regardless of your judgement about the effect of OBS, she can run as long as she starts before F1 has the ball in the circle. I know you know that, but others are reading.

If she did not run to 2nd, then it's a question of where you judged she would have reached w/o OBS, probably 2nd from your description, so if she stayed at 1st - award 2nd. I know you know that, but others are reading.

As to F4, it actually made no difference unless you would have kept her at 1st if she didn't run to 2nd; but either way you said nothing so F4 should have tried for an out (assuming no runner on 3rd).