She's not only the smartest and most functional of the deathfat cows here (as well as the smallest), but she's also one of the most profoundly, actively malicious, while draping her malice in the banner of "activism."
Growing up as a seriously ugly girl is really hard. Being a fat girl is hard. Being a book-smart girl is hard, especially when you're working class. Being Latina has its difficulties as well. She's at the intersection of all five—which didn't guarantee that she'd turn out to be a malignant Narcissist who hates any woman prettier, thinner, more affluent, and/or whiter than she is, and seeks to tear them down in any way she can, but unfortunately, that's how she turned out.
She really, really hates other women. She takes pleasure in either actively encouraging them to destroy themselves, or accusing them of being oppressors in need of re-education for making simple, everyday choices for their own well-being.
Virgie is malicious toward other women in the same way that Kelly Lenza, Marissa Matthews, and Splotchmaker are. It comes from envy, and rage at not getting the kind of attention they want, and feel they deserve. What makes Virgie different is that she's actually able to focus that malice into more than just pathetic social media whining; she's turned it into a second career in which she writes and speaks about fatphobia from a semi-academic perspective, in an authoritative way.
If she wasn't so physically repulsive, I'm convinced she'd be a lot more dangerous than she is. Unfair as it may be, humans have a natural inclination to avoid other humans who are deformed, clearly unhealthy, or genetically fucked into hideousness. We're still animals at rock bottom, and other species do the same thing. The big diff is that humans can change their minds and come to different conclusions about individuals on a case-by-case basis, based on their words and deeds. But Virgie's words are, frankly, pretty fucking insane, and appeal only to other defective people, or those whose income and professional reputation relies on pandering to them.
(And for the love of god, do not post that tired Roald Dahl meme; however true it may be, it's been done to fucking death.)