Ex friends are posting mean things about me on Facebook, how to I make it stop? :(?

[beautysonlyskindeep. <3]

Basically- I kicked my friend out of my group (charity, not group of friends) because she was manipulating people, gossiping about my friends, and trying to control everything. She responded to this my divorcing me on Facebook, dissing my group ("immature juniors", I'm a senior), saying she won't talk to us ever again, and by posting mean things about me. She posted something like "At least I don't have her face", her friend commented on their new FB marriage (using our date...), that "at least it is a step up", and a few of my ex friend's friends are posting a bunch of mean stuff about me. I wouldn't mind if it was just my ex-friend, but a bunch of people (including her friend's parents) are posting horrible things about me. I'm almost 18 and I'm trying to be an adult about this- I don't wanna be rude and say mean things about them. But I doubt they would talk to me, even if I tried to talk to them. It hurts- especially when they called me ugly- they know I'm self-conscious about my appearance, yet they would post that. I'm so furious, but at the same time I wanna cry. What do I do about them, especially my ex friend's friend's parent? I feel like they won't stop :/
Both of them were bullied in elementary school- and they know my insecurities which makes this work. I think I'm gonna start off by blocking them on Twitter, so they can't post any more mean things.