The way she looks at those flowers... that's not very different from the way she lovingly looked at food. She's not thinking of eating those too, is she?
I'm surprised Celestria didn't think of telling Jelly to heal herself with her own power, but I guess she felt that she had to return the favor for saving her from that scalding tea. Also good thing it didn't do anything to change or reveal how "Jelly" is technically a human body inhabited by a slime, with slime fluid instead of blood flowing in those veins.