For her sake, I really hope that the actress they cast either doesn't have social media or hands over control to someone else. Bella Ramsey has spoken about the horrible time they went through reading the nasty comments about their appearance on social media. Thankfully the cast and crew seem to be very protective of one another and Craig Mazin and Pedro Pascal looked out for Bella so I'm sure they'll do the same for Abby's actress but there's no way that the internet is going to have a calm, reasonable reaction towards the actress that gets the role.