You know, this could actually become a genius new way of defining Poison Ivy's origins on a BTA's Mr. Freeze level!
It is not regular Poison Ivy ... it is Adult Poison Ivy with THE MIND OF A CHILDREN
Think about the undertone of the scenario:
"A 14 year old girl get touched by a monster and has to premature deal with her sexuality."
This actually makes her growing insanity and hate for humanity much more relatable, then a simple scientist becomes Super Hot Plantlady story. Insanity always has something to do with tragic and this would actually give her a good and dark history. Especially since we know the small, poor girl in the beginning and we want her to become normal again.
Of course the execution is important ... But the idea is great and much more in tone with a modern, psychological Batman story.