It also seems much more likely

She has some Jedi Rage/Grey Jedi like Young Obi-Wan ( no relation) accents are not inherited - and Luke her father...( Im calling it now, its not too obvious..we all thought she was a Solo). Anyway just like young Obi-Wan and Luke when they first started out Rey has to master and control her Jedi Rage. We already have a Solo-Skywalker who is yes worse than Vader..Vader could redeem himself..Ben Solo/Kylo Ren is now warped and more twisted making him unredeemable...and he killed his father, hard to come back from that. Kylo Ren will probably end of dying at the hand of his Uncle or Cousin or both.

If Rey ended up in the dark side it would be an interesting plot to see if she stays dark or if she returns to the light like anakin did

There's already one character for a redemption story. Turning Rey dark side too and redeeming her would just be too twisted and complex. Plus audiences in general prefer to be told the story from the POV of the good guys.