I really struggled to be able to see the bottom and top items on the same dopesheet at the same time. I tried following Rick’s clicks (a rhyme I’m sure he’d approve of) but it kept forcing me to record each child object separately.
I was also unable to manually use the Add Property button to add the transform.position for bottom to the top animation. odd.
The solution seems to be, when setting up the Trophy animation for the parent object, to select both children at the same time, then hit record. This will establish the dopesheet with both child objects on it, and then I was off to the races.