I am going to loose my license on wed for a drink driving charge. I'm expecting 3 months disqualification and I have to go back to Brisbane (currently in Tasmania) so the car is going to be sitting at mum's place until I can pick it up later in the year. She is going to drive it every now and then, but no where near the amount it is usually driven. Is there anything I need to do to prepare the car for sitting around not really doing alot? I have just given it an oil change, the battery is only a couple of months old and all other fluids are less than 3 months old.

Should be fine to sit for a while mate. If the oil and battery are fine then I don't see any harm done. They should both last long enough.
Just get your mum to give it run in the garage or wherever every week or so, and give it a bit of a drive every 2-3 weeks.

I'd just let it sit with the batt off and s**t all fuel in it.
Wheb you go to get it just take a Jerry of premo there. Driving it 1 tine a week would probably be worse then not driving it at all.
Would leave a lot of water in the exhaust.