Not sure if this will help, but my overall suggestion would be not to worry about what is PG enough sounding. Your role isn't to determine that really, just to share information so they can determine if it sounds like the program would be a good fit and would be helpful to him. If it is a good fit cool - if it isn't good to find that out too. I would suggest picking whatever examples you think you can comfortably write about in more detail. Often it really isn't just the specific milestone but how it came about and what they do with the activity that is important. Hope that helps.
