You had me until "in a parallel universe". Is this a heist/revenge drama or a sci-fi alternative reality movie? You are mixing two genres that generally do not go together. I would suggest adding the word "inner" before "demons", turning that semi-colon into a period and dropping the ending fragment.
From your log line it seems as if you were going to concentrate on the fact that she was abused and going for revenge against those who wronged her which would totally work BUT then you tack on the sci-fi add-on which doesn't make any sense. If you're going to write sci-fi, write sci-fi. If you're writing a psychological drama, don't dilute it by arbitrarily throwing in elements that may ultimately weaken your story.

I really love the parallel universe aspect and think you should rewrite for sci-fi as Anthony suggests. "inner" makes sense also if you are not going sci-fi.

I have to agree with James and Anthony. The parallel universe aspect is really what can make this story unique :)

Thanks for the feedback. I wasn't going for sci-fi. I'll go with inner demons. The point is she does "see" her sister but it wouldn't be revealed until the end that the sister is only in her head because she died and was a twin. BUT since I am still in the preliminary stage I might go with sci-fi. I will have to see where this story takes me as I develop it with this course.

Nice story. Good twist at the end.