Allow me to beg your indulgence, for just one moment. It's my firm belief that AJ's seemingly abundant screen time in S3 is long overdue, compared to her past appearances in the first two seasons.
In S1, she arguably has one episode completely centered around her (Applebuck Season), and three episodes where she shares the story's focus (Look Before You Sleep, Fall Weather Friends, Over A Barrell). I'm excluding any other episode where she may have made a brief appearance; safe to say those don't count.
Then, in S2, she plays a somewhat minor roll in "Sisterhooves Social", and less of a minor roll in "Super Speedy Cider Squeezy 6000". And then there's "The Last Round Up", where it seems the fandom will forever remember that episode for Derpy, and not AJ
Sigh, the fan boy inside me wants to say she should get even moar screen time, but that would be unfair. All I can say is that it is good to be an AJ fan in S3.