I completely agree. I know kids these days can be horrible, but if there is anything I learned while being picked on growing up is that if you ignore them and show them it doesn't bother you they get bored and move on. Being thick skinned can help you out a lot in life.
I've seen a lot of stories about kids being bullied online and always wonder why they didn't just block the bullies.
I also hate to say it, but I think it might be a good idea to bring this to the attention of your ex-husband. You are 3 hours away and he needs to keep an eye on her if you are worried about her.