Forgive me if the assumptions I'm making here are incorrect, obviously or belittling. It seems you're an engineer trying to help a PM here. Ideally they can get

Forgive me if the assumptions I'm making here are incorrect, obviously or belittling. It seems you're an engineer trying to help a PM here. Ideally they can get mentorship from a more senior PM inside or even outside your organization. I stress finding mentorship because what you're bringing up speaks to this individual not quite getting one of the key pieces of a junior PMs job - controlling scope. If they don't understand that and iterative development they likely need a larger education in the job itself and how to be effective at it.