Last night my daughter reported her car died just when she got home and wouldn't restart. This morning I dropped by and it started right up and there was a code for Crank position sensor malfunction. I cleared the code and took the car for a test drive. No problems.

Should we just preemptively replace the sensor or wait and see if the problem repeats?

Car is automatic transmission, wagon, less than 200,000 miles.

pretty old so, hard to argue about changing it. They are not overly pricey. User @lmdew might have some used ones.....

If you want to experiment, clean it. They sometimes collect enough rust/ferrous particles to become intermittent. But, be prepared for it to not come out in one peice. They sometimes are corroded in-place.

How old are the timing system components?

We changed the timing belt, pulleys, water pump about 20,000 miles ago

EBay has an OEM sensor for $9.79

I have plenty.  USMB Donation and the shipping.  USPS Flat Rate small box.  I think $8 now.

Could send a few and other sensors if you need them.