I've been on single parenting payment for some time. At tax time if you haven't worked you need to advise of a non lodgement each year. At tax time, usually in July, centrelink balances your payments, which usually results in about $1000 payment. Karlie would most likely have received that. The immunisation register is updated through the doctors/nurses records at the time of immunisation.
Centrelink can request you to come in for an appointment for various reasons. Pretty sure I've had one that was referred to as a 'personal contact appointment' or something along those lines, and there hadn't been any change of circumstances at that time. If you do not attend the appointment your payments may be cut off.
I find it strange that the woman in the wheelchair impersonating Karlie was with a man...she was on single parenting payment so that is a bit strange for me..
Thanks Melissa, it's good to hear from someone who has some experience in these matters. It's one thing to try and work it out from all the various links, but unless you know something about the actual reality of the situation, it can be hard to fathom.