Hm, now that u mention it, i get the Sara scene now, but the WT says there should be a hug and a bit of extra...i don't get that either.
From the WT it seems the only condition is, to be on Saras love path, her love path seems to be triggered after the tennis match, where u have the choice ''to act affectionate'' so i guess it's a problem with that choice...i try start a new game, let's see if it helps.
Edit: so new game doesn't help either, no idea how to get that hug scene (or if the WT is wrong).