Most people recommend using a separate battery, to avoid issues with power fluctuations, and draining the house battery. That said, I always run mine straight off the house battery using the supplied alligator clips, without any issues. It does mean there is no fuse in the system however. They normally draw about 10A working but can draw up to 30A on stall, so any wiring/fuse/plug needs to be able to handle such loads.
The wires in the power cable where it enters the reel are prone to failure due to overbending so avoid stressing this area, and treat your wife to a spare cable. They aren't cheap ($100+) but nor is having to abandon a trip out wide.
I've known a couple to fail due to water getting in to the motor, so protect the reel from spray when you are driving the boat, and be wary when washing it - a wipe down is probably better than a rinse with the hose.
If you are out wide looking for puka/bluenose during summer, you may well be in gamefishing country, so you should probably buy your wife a couple of game sets as well