Three possible ways to triangulate "red" check engine light
1. Straight below the F on the fuel gauge.
2. Slight below and to the left of the trip meter reset button.
3. If you extend a line from the speedometer needle when the car is off.
I'm using a 1990 325iC and 1991 318i as my reference points. The check engine indicator should light up temporarily when the ignition is in the run position prior to starting the car.
With the 90, I wasn't getting the cel. Traced it to not having a 2721 bulb in the holder. I had the padded trim panel below the steering wheel off because I was troubleshooting other issues. With a long pair of straight needle nose pliers, I had just enough leverage to reach up, pull the holder out of its circular housing in the instrument panel, press in a 2721 bulb, push it back in, and I was in business.
Props to your family -- I served in the Air Force for 20 years.