I think that you answered your own question. It is not enough for the fielder to block the baseline. If we would have OBS on the short stop every play
. The fielder has to NOT have possesion of the ball, clearly she does not, AND impede hinder or confuse the offensive player. And from your description she did not. Now as Bluefoot mentioned this picture is one that could make one jump to conclusions and think she deviated due to the F2's leg being in the baseline, but a single moment in time photo does not show us all what happened. She might be exactly in her chosen basepath and did not deviate, maybe this is a team of hook sliders, seeing the F2 setup in front of the plate she is planning on sliding in and catching the back corner on the way by to avoid a possible tag. Important thing is fielder position DOES not matter UNTIL they cause the offense to react (without the ball) then we have OBS.