Can a second parent be added to track location of a child’s Apple Watch

Set up son’s Apple Watch. For more info, he doesn’t have a cell phone or iPad. Watch has cell service. There are two parents in the family group but only the one that setup the watch can track location of the watch. I’ve gone through every instruction i can find to add the other parent but they still can’t see the watch. My daughter, another minor can see the watch when added to tracking!

How can the second parent track the watch? TIA!