Twitter is a private business. She can block whoever the hell she wants.
But can Trump?
Did I stutter when I said private business?
Yes he can
Actually, Weatherman's post number 7 has a good article on this. And, since Trump became a public figure, his twitter account was ruled to be a public forum, because he uses it for policy.
AOC is using her twitter account as a public forum, and therefore, she cannot block anyone either, at least, not until after she leaves office.
What's good for one side, should be good for the other. If Trump can't block people because his account is a public forum since he uses it to post policy, AOC can't block people either, because she is also using her account to post policy, making it a public forum as long as she is in office.
(Yeah................I know...............you conservatives are flipping out that a loony liberal such as myself would go against AOC, but what is right is right, and the same standards need to be held for all public officials, regardless of party).