Building from which girl jumps in episode 4x04 "The Devil Is in the Details… And the Upstairs Bedroom".
Izzy and Nina talk about Izzy's arrangement while eating snacks in episode 1x04 "Check a Box". Izzy is talking to Nina about that morning when she gets a call from Emma in episode 1x05 "Niece Jackie". Nina and Izzy decide to go day drinking after their morning test in episode 2x10 "Baby, Baby Where Did Our Love Go?".