system
Given the following post, respond as if you're commenting on Reddit:
human
[Encanto/Tangled] Can Isabella grow the flower that gave Rapunzel her hair?

Assuming this is all in the same linear Universe, of course.
gpt
Given that the flower is not unique, and can be seen also growing on the island of Motunui (Moana) as a result of the nature god/power returning. It would be reasonable to assume that another source of magic/nature could allow it to grow. 

The only drawback may be that (currently) Isabella does not appear to have such a fine level of direct control over her power, and creates flora mostly based on feelings/mood. So would need to refine her power to do it on demand, or would need to see or 'know' the flower first to grow it.