Younger, why? we are never told her age but we know Ivy was already working with the Floronic man when "The Gardener" joined the group and she looked up to Ivy in that group (I doubt somebody would look up to somebody younger). Current Ivy does not age (or does so very slowly) so we can't really go by looks. These are all assumptions of course.

How do I know this? I read Batman: Secret Files when I saw Ivy on the cover while scrolling through DC Universe Infinite (paid the membership, might as well use it). I usually don't read Batman comics but I really like Ivy so if I know she is in the story I tend to read it.