Could Marcia Cross have made a good Pamela Isley/Poison Ivy?
I never thought that Uma Thurman was that attractive (she's more quirky/offbeat looking then an out and out "bombshell") to make playing a seductress like Ivy work. Plus, Uma's choice to play Ivy like Mae West on steroids just makes the movie feel schlocky and tone-deaf. She isn't exactly convincing as an unhinged, vamp like Michelle Pfeiffer was as Catwoman.
https://www.google.com/search?q=Marcia+Cross+green&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjWtvui1ILeAhXrRt8KHbNMAKAQ_AUIDigB&biw=1440&bih=785