If you've got family, then have a plan.
We did have a rudimentary plan, SWMBO and our son worked / went to school in the CBD, she parked her car in an open space away from tall buildings, if anything happened, then that was a meeting point. Then the plan was to get home. There was no reliable cellphone contact including SMS in the CBD in those hours after the quake. It took about 5 hours before I got a message - our landline was actually still working, SWMBO had seen the son of a friend in town, he made it home and his mother called me to say she was okay, but another couple of hours before an SMS was delivered to me saying that our son had made it to the pre-arranged meeting spot, and they were about to leave. By evening, the local cell towers were out. Mains power was down and cell tower backup batteries didn't last long. I've heard that cell tower battery backup is better now, but can't confirm it - "I read it somewhere". I wouldn't count on it being useful - as despite pleading messages on the radio to limit use to SMS, the networks were hopelessly congested.
It was not a very nice afternoon. Our landline rang constantly, most land-lines were down, me running messages from people who'd contacted me to try to get messages to neighbours. Kept me busy though - which under the circumstances was probably a good thing.
The September 2010 quake happened before dawn. We had no significant damage (alas not the case in Feb 2011). Torch near the bed is a good idea - and some easy to don shoes. Feb 22 the contents of every cupboard ended up smashed on our floors, large plate-glass windows exploded. Shredding your feet on broken glass while panicking in the dark would add misery on top of misery.
Never had any problem getting radio, a cheap battery pocket radio was fine, car radio was there. We do tend to keep cars topped up with fuel these days - my 4WD was low on fuel, and days later there were massive queues at the service stations that were open.
It might be a bit different when Wellington is hit, as there's a good chance that all road transport will be cut-off, so emergency food supplies will be by air or ship until roads are restored. In Chch the supermarket chains did a commendable job getting their stores cleaned up, open, and stocked, apart from some panic buying (bread FFS - not sure why people panic buy bread when it goes mouldy quickly). Fresh water is a no-brainer, decent first-aid kit, pet food, canned/dried food, something to cook on, a few tarps and ropes could be handy, she'll be right.