Bay, Daphne and Emmett trying to get into the closed club:
Emmett (signing): So I'm just going to keep nodding to her while signing really fast and throwing out random words like baseball, grapefruit, tiger, rice pudding...because hearing people always get really uncomfortable and give me what I want just so I'll go away.
Daphne's story about Emmett protecting her from mean 3rd grade girls when they were kids.
Bay goes to discuss the custody battle with Emmett's father. Upon hearing how his main concern is not letting Melody win she calls him out on it. This response makes him decide to give custody to Melody.
Bay signed about the guitar case in either episode 6 or 7. Considering that she just started learning, the casual and distracted way she did it is an impressive feat.
"Uprising" was a logistical accomplishment for the whole cast.
As John points out, Bay transferred from a regular school for a school to the deaf... and stayed.
Bay stopping a student from commercially exploiting her Hammer Girl work on offensive T-shirts in "To the Victor Belong the Spoils." He has the law on his side under the right of fair use... so she goes old school. She tells his mother. Job done.