Find Becca dialog and game play...
Yeah... the sequence is a little screwy. It is because, you were paying attention to the dialog and new instinctively that Becca was at the stables (Because Priscilla JUST Told her to go to the Stables)
But the game wants you to go through the process of:
1) GO to the mall/movie to meet Becca ... (where you talked about going together
only to find out she is not there... duh... you just heard Priscilla tell her to come to the Stables after school)
SO YOU"D THINK YOU"D Go to the Stables right? Since she is not at the movie, you got to the stables because you just heard the conversation above......
2) But you'd be wrong, you now have to go look for Becca at her house, have a dialogue with Becca's Mom
3) Now you have the quest prompt! And you get the bright idea to... gee... go to the Stables!
You can't do any of this out of turn either, or you won't get the right quest.
4) Check out the Stables... witness the interaction
5) Go to the house... oops... first got to go to the front to witness another conversation between Harry and Gerda
6) Go in the house to Priscilla's Room - Check her drawers for key
7) Go back to stables...
I think Lost Raven could fix it with some dialog. The player knows what to do, because he heard the conversation between Priscilla and Becca...
So quick fix is muddying up the waters so it is not clear where Becca is..
"Uhhhmmm gosh, I dunno Priscilla... I am not sure I can come to the stables. I was planning on going to the movies tonight. Uhhh... I probably have to check in at home too".
Add that dialog and it will be unclear to the player where Becca is.... but the player should only have the prompt to go to the movies at this point, so they can at least start there. Or, in an update, skip the whole part about going home and checking with Sara...