:-) No need to be embarrassed.

Upgrade offers will appear in the reservation when you open it in the app. For example, on an upcoming trip, I see "Enjoy our premium cabin Upgrade from $169 per person" (ORD-AUS, in this case). You likely won't see this -- yet -- on your wife's reservation, as you can't normally upgrade award tickets until check-in.

After check-in, you should see it on both reservations (if there are seats available). For checked in flights, you'll see another menu pop up when you tap on your reservation; select Travel Options, and the upgrade offer should be shown there.

You can also find it on the kiosk at the airport, or on the website, but the app is likely to be the easiest.