When Cheyenne's mom tells Amy she's "not engaging," her arm jumps from on the couch arm to off of it between camera angles.
When Cheyenne's tells Amy "you're not engaging" the cup disappears from the armrest between shots.
Cheyenne says that Amy is old because she was alive in the 90s. When the series started in 2015, Cheyenne was 17 years old, meaning she was also alive in the 1990s.