I said:
As an avid fan of Bloom and Wild, I am contacting you regarding an Instagram advert posted by the influencer, @rvk_loves.
I have to say that I am very disappointed that you are working with her, considering that she tweeted about how much she hates your flowers. I have attached a screenshot of said tweets to this email.
I always hope that when influencers share adverts on social media it is because they have a genuine like or interest in the product yet she publicly stated online that she hates the company.
Hopefully, you'll not use her again for campaigns and be more diligent when sourcing influencers.