How exactly does Soraka's Rejuvenation work?

I've played her some decent amount but I guess because I can't multitask I can't really see what goes on. I knew if Soraka hits and enemy with her Q she gains rejuvenation (she gets health back and also movement speed). I also know if she heals an ally the ally also gets the rejuvenation. What I'm curious is what happens if she heals to different allies while she's in rejuvenation. Do they both get it? And also does soraka still keep her rejuvenation while healing allies, or does she 'lose' it and 'gives' it to an ally instead. Also what happens when she ults during it too? I'm sorry for all the question. I'm just curious but I can't figure it out in training mode.