How to counteract Yuumi?

Hello, this is my first post here! I am mainly a soraka / nami / karma support, i go adc sometimes too (mostly Jhin).

But if the enemy team has a Yuumi, which is actually so annoying and I don’t know how to properly help my adc for that, any suggestions? Should i practice and change my support/adc character ? Thanks :))

Edit; Majority said to just ban her, but sometimes my team tells me to ban someone else / I accidentally lag and go afk so i missed the banning phase :((