Insecure can be defined by many things. For one, if someone has to constantly repeat how great or attractive they think they are, clearly they're not entirly sure about it. They might be trying to convince themselves it's true. 2nd, they lie. A lot. This is because they're too ashamed of their own lives to except them for what they REALLY are, so they make up people and situations in order for their lives to sound a little more exciting. 3rd, they're easy. As in, they would go to third base on a first date. They need either a lot of guys or girls approval in order to be confident with their appearence, love life, exct. And lastly, they put other people down. They'll make an unecessary, rude comment and try to pass it of as a joke. Call them out on it and they'll say that they really don't care. But if they're even taking the time to respond, then they obviously do.
The insecure girl really needs to get over herself.