She will erroneously confuse players with Lady Maria, but soon understands her mistake. Then she will beg her new acquaintance to fetch her Brain Fluid, something that will allow her to keep her focus on a "sound" she hears.
Research Hall, enter the room with 3 elevators & 3 enemies in wheelchairs on the 2nd (or maybe 3rd) floor and take the elevator on the right as you enter.
Is that you, Lady Maria? No, you're someone else. Please, could you do something for me? I need Brain Fluid. Murky, mushy Brain Fluid.
After giving one Brain Fluid
Oh, thank you, you're terribly kind. Ohh, it's wonderful. And, oh! I hear the sticky sound. Do you hear it, too? Oh, I know. Will you have my blood, as thanks? I'll have you know, I was once a Blood Saint, too.
She drops the Balcony Key if killed. But killing her stops her questline, as such it is not reccomended to do so.
She addresses the player as Lady Maria when first spoken to, but quickly realizes it isn't her.
Curiously enough, Adeline seems to have a head that isn't as pinkish as the other Clocktower Patients, but rather a slightly blueish one.
Another curious thing is that unlike the other "head-only" patients, her body is nowhere to be found. It would make sense for it to be strapped on the chair at the very least, but it is not there. It is as if her body was devoured or absorbed by her own head.