- She perished in the fire which engulfed Collinwood.
We know she survived the fire because Quentin mentioned seeing her in the East Wing room and that there had been a fire.
- She was killed by PT Prof. Stokes.
- She was kidnapped by PT Prof. Stokes.
I believe Tim Stokes perished in the fire.
- She killed herself when she realized she would not see Barnabas again.
She may never have given up hope that Barnabas would return, so I don't see her as suicidal.
BTW:
- She escaped the fire and PT Prof. Stokes, but was never seen or heard from again.
- She escaped the fire and PT Prof. Stokes, and started a new life apart from the tragedies of Collinwood.
Tim Stokes was a scientist (and a mad one at that), but not a professor.
- She returned to the fire gutted Collinwood of PT to look for Barnabas, and inadvertently crossed over into regular time where she eventually found Barnabas and filled the gap left by Angelique's death in 1840.
Hmmm, if she did, I imagine she'd find that the gap was already filled by Julia.