She's going to get it, too. At least online from ana-chans. AN can warp your ability to have any filter or give a shit about being nice- patients are single minded and fixated on their goal. They can be very, very nasty if you try to get in the way of their restriction or worldview.
Mocking Holliday mercilessly will be part of that single minded focus- they want to make it clear she's not part of their club. They will viciously try to distance themselves from this giant fatass and her horrible, horrible constant food pics (consuming food openly becomes an object of disgust).
The response from them will be 10 times worse than mere incel trolling. And she won't be able to dismiss it- she can't write them all off as losers. Maybe she'll just say they are obviously bad because the demographic of online ana chans are majority white.