Issue with Illaoi is she is a tank version of Zyra that has the lane bully effect of Darius

The best balance option would likely be nerfing her early game and buffing her late game.

And I have seen a shen with Udyr and a cannon minnion wave lose to her and 3 minions when level 4. She didn't even have to burn flash.

This is why I am saying her early game is too good especially once people start learning to play her.

If her late game is too weak the buff it but her current early game is really oppressive for many melee.