As Firo explains his condition, Rey squints a little. Yes, she can sympathize a great deal with that...

"Have had that problem since before the recon. Can't help make it stop, but perhaps there's a way to help you better live with it."

Without her father's guidance, Rey has only her memories to go on. Fortunately, her memories are all she really needs, as she can allow herself to go back to that old moment of another time.

Of course, Firo's situation could be different from hers. But she's willing to help.