No, no, no. I've watched the sequence about a dozen times. In the film, she never has time for this kind of contemplation, nevermind execution. Even when she begins pummeling her opponent, she doesn't circle Kylo Ren, she breathes for a split-second. She's in the middle of a fight for her life, she can't be expected to smile.
Her "stabby" Palpatine-like lightsaber moves aside, I don't buy (from purely watching the movie) that Rey is lured in the least by the dark side. Given how the scene starts ("you're a monster!"), she is obviously disgusted by Han Solo's death at the hands of Kylo Ren and she then hears Finn being hurt by Kylo's saber, but any action on-screen beyond her initial attack (complete with Palpatine-like stabby lightsaber moves) never shows her losing control and giving in to dark feelings.
When Luke attacks Vader at the end of ROTJ, the pull of the dark side is definitive -- from the beginning, he starts swinging his light saber in anger, the rage is made even more apparent by his repeated downward thrusts as Vader lies half-way on his back. After he severs Vader's hand, he looks at his own and contemplates what he's become.
Rey, on the other hand, meditates. Again, going by the movie only, Kylo Ren propositions Rey with dark side knowledge, but she deliberately attunes herself with the light side of the force through meditation, and she unleashes it in a way that is more self-defense (getting herself out of a shit situation) than obviously dark side. Just because she beats Kylo Ren's ass doesn't mean that the dark side has taken over. She clearly, for whatever reason, is more powerful than Kylo Ren. We may disagree on this (you could say that Kylo was injured already), but this is likely deliberate by the filmmakers. When they fight again, and Kylo is not shut in the guy by a bowcaster, will Rey stand a chance? Who knows. We'll see.
In this movie, she puts him on the defensive and never lets up because letting up would be certain death at that point. Her only defense is offense.
I have a hard time with this sequence because it is unlike what we've seen in the past. Rey should not have this much power so easily. The novelization describes it as rage, but JJ failed to film it that way. At no time, in my dozen viewings of the actual movie, do I believe that Rey is even contemplating the dark side anymore than I thought Yoda was channeling the dark side during his duel with Dooku in Ep 2. The key take-away from this duel being that Rey is very strong with the force.