I was told by a pretty good source that it was an attempted suicide and she had planned to crash into a landing aircraft. That isn't confirmed though and should just remain a rumour for now. The incident, although serious, was not terrorist related in anyway, just a person who is a few slices short of a loaf.
It does highlight the fact that you cannot secure every inch of an airport and when it comes to vulnerability a chain wire fence is no protection. All the AFP, security personnel, security patrols, passenger/freight screening, bag scanning and body scanning and ASIC's won't prevent a loony in a car crashing through a ****ty fence and reaching a runway or parked aircraft in under 20 seconds........it's a fact of life.
It does give you some food for thought and a reality check as to how vulnerable aviation is. Now we also have drones in the hands of idiots and we have places like Botany Bay where you can park a kayak and walk onto a runway, yet we pay millions upon millions for "security" and peace of mind? Folly.