Since we’ve just been talking about how Leia was such a good potential Jedi and how she wanted to use nonviolence, would it make sense that Leia had discovered this Force Healing power and taught it to Rey?

Rey: It’s in pain. I can sense it.
(Rey hands her saber to Finn)
Rey: It doesn’t want to hurt us.
(Rey heals the snake)
BB-8: Questioning beep?
Rey: I just transferred a bit of life. Force energy from me to him.
BB-8: Beep?
Rey: Leia taught me that.

This makes her healing Ben with this power a lot more meaningful since it comes right from his mother, and may imply that Leia is giving the last of her life energy to aid Rey in healing Ben.