Shes not immune to electro and the best strat is to have at least 1 electro in your party to quickly destroy the flowers to avoid the 1 hit ko attack. The flower takes extra damage from electro.
In other news, I think they broke the tea pot. They are giving out 5k realm currency per Week that its still undergoing maintenance. So they are expecting this to take awhile it seems. Id much rather have primo gems then realm currency. Just hope with it taking so long that theyll up the capacity.