The problem is that “power” doesn’t necessarily mean darkness in the context of Star Wars, which is what we’re trying to get at here. I also don’t think it’s worth stating Rey’s future role as a sentinel unless it was somehow what Leia aspired to be, thus she’s continuing Leia’s own path in her stead. So…

"She was quick to learn in our training. But Leia was vigilant of her potential darkness, choosing instead to serve the people, as our mother once did. She surrendered her saber to me, and said it would be picked up again by someone with a spirit to ward off the dark.”