14 is old enough to know whats wrong. She wanted attention, so give her some, the legal kind.
Not really. A 14 years old can't vote, can't drive, can't buy alcohol and can't have legal sex in lot of places. You can't have a double standard. If they are not old and mature enough to vote, drive, drink and **** then they are not old and mature enough to grasp the gravity of what they are doing.
It's okay for the police to investigate but it should not go further if there's no proof she was going to act. At the very worst put her on some sort of check list at air ports.
Also i hope they did not get her ip from Twitter. It's police job to get such information and if Twitter handled them the info without a proper warrant this is not right at all and this is morally as worse as what she as done.