Her first mistake was not looking up. Sara dropping her call sign means she's mad as hell and there's more important things to do than strap in a pair of jet boots. 

On the other hand... jet boots! How often do you even get to say those two words together? She could have gone for the wingsuit, obviously, but that was a tactically unsound decision and she knew it from the get-go. You need training for those things, and for once she doesn't have it. Moreover (and this is why), it's a powerful piece of machinery that tends to supersede the user's own physical parameters. In her case this is an especially stupid idea. But she still needs to be able to land without breaking anything, fight off more heavily armored opponents than usual... unless she wants to try suplexing more TAGs today, and probably jump higher in a move than she can on her own. Hence, the jet boots. She stands, slings the mirror (which for some weird reason is shaped like a kite shield, but you won't catch her complaining) over one arm, adjusts her handy new shock gloves, turns around and then... uh oh. 

There are wings. On her face. Euna is literally looking at an angel right now, and she feels her breath catch. For one delicious moment, she blushes and stares at Sara with stars in her eyes and doesn't care whether or not there's a stream watching her making stupid kissy faces because a pretty girl flexed near her. It's not like the elevator this time. It's... it's...

She freezes. The words sink in, and her face hardens instantly. She rushes around to Sara's front and gets right in her face. Don't think about how she has to look up to get there. Don't think about the lobby or the game field, or any of that. She takes a step forward, and dares Sara not to step back. 

"Hey," she snaps, "Hey! If you're mad you're mad, but this is. Not. The. Time! I don't wanna hear it! There are people down there in danger, right fucking now! So we're not divvying up the kills right now, you got that? I will not 'wait up'. You will fall the fuck in line and you will get your priorities straight right fucking now, or I will drop you like a bad habit and take out Victoria and the 'evil computer' with the functioning part of my team while you take a nap. Get me? [i]Good.[/i]"

Her eyes are burning. She did [i]not[/i] fight her way through the entirety of AEGIS by herself to put up with this shit right now.