Just to further what is actually in the vision, this is from the official screenplay Disney used during awards season:
“A little girl. Rey as a child. She is sobbing, hysterical. Unkar Plutt’s meaty hand holds her thin arm. She is on Jakku, watching a starship fly into the sky, abandoning her.” Rey yells, “No, come back!” and Unkar Plutt responds, “Quiet, girl!” as the “ship flies towards the desert sun, which is strangely eclipsed, as if being eaten by darkness.”
The shot of Kylo and the Knights of Ren lists a ‘Warrior’ being killed. I, too, thought it was Zuvio when I saw the film. But that doesn’t make sense chronologically.
Also, it is Kenobi that speaks to her. Ewan McGregor was credited as coming in and doing voice-over work.