If you consider what items may be susceptible to moisture the list is
reasonable.

In general, ignition is the usual suspect.  Check the Distributor cap for
"carbon tracks", moisture and general condition.  Arcing along or near the
plug wires can do the same thing.  Condensation is a HV leakage path.

I would replace the plug and coil wires, distributor cap, and rotor. as a
matter of course.  The connector for the O2 sensor can also be suspect.
Disconnect and clean.

At the very least she should appear in person on Click and Clack the
Magliocci Mechanic Marvels and present the problem to them.

pensioner