Katie Nolan is the half-sister of Kelly Severide and daughter of Benny Severide. She has been to the firehouse twice and as of episode "Shoved In My Face" has shown romantic feelings for Brian "Otis" Zvonecek. They were playing Catan and shared a kiss.
Even though Kelly was only her half-brother, they grew very close in season 2. She rejected him at first but eventually accepted his invitation to cook for 51 as a way to train to be a catering chef. After that, she came around often. Kelly was visibly very protective of her since they met, including intimidating Otis when he tried to flirt with her.
Kelly also seemed to be closer to her than her own mother as her mother is always occupied with her twin sons. This was seen when Severide was the only to attend her graduation from Culinary School. Also when she gets kidnapped at the end of episode 13 Kelly never gives up trying to find her and when he does, he's mad to see his sister very upset and beaten.
Katie is kidnapped by Vince Keller and one of his buddies in Tonight's The Night as revenge for Severide humiliating him at the Firehouse. In Virgin Skin, she is found bruised and beaten. Since she is traumatized by the attack, Katie leaves town for a fresh start after accepting a job offer in another area.
|Season 2 Appearances|
|"A Problem House"||"Prove It"||"Defcon 1"||"A Nuisance Call"||"A Power Move"|
|"Joyriding"||"No Regrets"||"Rhymes With Shout"||"You Will Hurt Him"||"Not Like This"|
|"Shoved In My Face"||"Out With A Bang"||"Tonight's The Night"||"Virgin Skin"||"Keep Your Mouth Shut"|
|"A Rocket Blasting Off"||"When Things Got Rough"||"Until Your Feet Leave the Ground"||"A Heavy Weight"||"A Dark Day"|
|"One More Shot"||"Real Never Waits"|