There's Another One?!

What the hell happened?

Jay rode in the back of the ambulance with Rose, "is she gonna make it?" He said impatiently. Brett looked at jay with doubtful eyes, "she's got good bilateral breath sounds but she's lost a lot of blood jay, I can't promise anything" she said while inserting an IV line.
Will was in the ER when the a gurney was rushed in, he was in a treatment room checking over a patients stats with nurse sexton. He was about to up the dosage of morphine on his patient when he heard Brett in the room next door, "Rose Halstead, double stab wounds to the shoulder, intubated in the field". His stomach dropped as he threw the iPad to April and left. He walked out into the ER to see jay all flustered and looking at rose being treated, Will pulled jay aside. "What the hell happened?" He said in a sharp tone. "I-I don't know she was laying on the floor by my desk when we got back to the station, she was meant to be at home. I don't know will..." he replied rapidly. The two stood in distress as they watched their younger sister fight for her life.
Rose was in a lot of pain and she was slipping in and out of consciousness, the doctors were ordering tests, lots of them. She was dizzy and her head was spinning until it all went black.
"We're taking her up to the OR now, follow me and you can wait outside" dr crocket said as they wheeled Rose into the elevator.
She had been in surgery for about 2 hours until dr crocket came out to find Will and jay, "hey, she's gonna be okay. She's under anaesthesia but she's gonna make it. The stab wounds were deep but they didn't hit any major vessels, you can come see her" he explained. Both of the brothers let out a big sigh of relief and hugged each other. "Thanks doc" jay said briefly while still trying to take it all in.
Rose was in her own room, she was sleeping. Jay and Will were both sat with her and waiting for her to wake up. Her eyes began to flutter open and she squinted as her eyes adjusted to the light, Will noticed her waking up and tapped jay on the shoulder. They both shot up to stand next to her, "hey rose? Can you hear me?" Will said while shining a light on her eyes. She didn't have enough energy to talk but she nodded. "Hey, we're here. We got you" jay said taking her hand into his. She closed her eyes for a second before it all came back to her, she jerked to sit up and winced in pain. Will gently grabbed her and pushed her back down since she was hooked up to a saline drip, "you gotta lie down Rose, take it easy" jay explains since she seemed out of it. "She's still drowsy, she'll want to sleep." Will said before taking jay out of the room.
"If you want to go update the unit you can, she'll be asleep for a while" Will said while nodding at jay. "Yeah, thanks" Jay agreed and left to meet the unit again. They were all sat waiting eagerly, hailey jumped up as soon as she saw jay walking over to them, "please say she's okay..." hailey begged. Jay let out a smile, "she's fine, she's gonna be okay". The whole unit sighed but since it was late the ones who weren't as close to Rose, like Vanessa and Adam, left after giving jay their best wishes. It was Hank, hailey, Adam and jay left in the waiting room. "How did this happen?" Hank said fairly angry, he thought of jay and Rose as family. "I don't know sarge, I got a feeling it's got something to do with a party her friend went to though" jay cleared up. Hank looked confused, "rose's friend ava went a party tonight and Rose didn't go because of her previous experience. They fell out over it and they haven't talked all day, I haven't heard anything about the party since last night. I don't know what happened but I'll find out..." he said getting angry too.