Great input from everyone, My thinking was I did not know why F3 did not make the throw, because of the retired B-R or because there was no play. Run would have scored easily even with a great throw home. Runner crossed the plate just as F3 turned to make the throw. Also I was thinking of a retired runner going to 2b on an attempted double play to 1b. But Steve M had a great point. The retired B-R had no reason to be where she was. I'm still on the fence as to if it was to correct call. Waiting for more input. Thanks

Well, it'd be tough to call INT on a play if there is no play. If F3 had no chance whatsoever to retire R1, then you have no INT. However, if she had a chance to make the play, I don't necessarily agree with "she had to at least make a throw." If I see clearly that she started an action, but was hindered and held up, then that may be enough to call INT, so long as she had the chance to make a play.

Now we have the full story !
I now have no interference .
If as you stated the runner would have made it easily and the F3 turned but the runner was nearly home then there was no out to be made and therefore no interference .
Please not as stated by other Umps NO THROW HAS TO BE MADE