Runner Safe or out 2
 

Ball is thrown to first base, first baseman drops the ball - as she is picking it up- she is in the baseline as the runner tries to get to first, Since she is basically blocking the path to the base is the runner safe?

Don't know, was she obstructed?

Being in the "baseline" is irrelevant to anything here. Was F3 in the base path, which is a line from the runner to the base? If so, did the runner react to F3's presence prior to F3 taking possession of the ball?

If the answer to both of these questions is "yes", then she was OBS and may have been awarded 1B.

My question is did she have possession of the ball before the runner, if she even did, altered her path the the bag. If the fielder had gained possession then you don't have obstruction.