Log out as Julie and Log back in as yourself. The bell icon shows you have a message saying the new teen group has been shared with you. Click the Groups tab at the top of the page. You should see the four groups that have formed.
Now click on the Contacts tab. The number of contacts is starting to add up. It is reasonable to assume, at some point, that there will be thousands of contact records in the data base. On the left there is a Contacts Filters tile. Notice the various numbers of people in the Default Filter categories. Click on the various filters to see who is in each of the buckets. Do those listed make sense? Do any of them need an update? As the admin and also a multiplier, you may choose to update various records or as an alternative, you could choose to @mention in a comment a teammate and ask for follow up, status update, or other information.
You can also click on Filters at the top. Here you will see the various fields it is possible to filter on. For example, you could see how many teen contacts you have or how many Julie is coaching to understand her workload. Again, if the filter does not yield the results expected, it is likely some information is missing from the contact record. If you find you are repeating the same search, perhaps with multiple criteria, give it a name and it will be added to the Custom Filters location on the left. Be sure to click Save in the Contact Filters tile to keep the named search.