Hi Jake! A few options:

1. If you are connected on Instagram, it’s easy to turn on notifications just for your teen’s profile: click their profile, and click the 3 dots (top right) then choose “Turn on Post Notifications.” You will get a notification every time the post — but not when they like.

For that, you can click the heart icon at the bottom of your screen, then click on “following” to see what everyone you follow has liked and who they followed recently. (though this is tough if you follow a lot of people.)

2. Trick: If you wan to go with the “following” route, consider setting up an account just for following your teen (with their knowledge of course) and then the only notifications in that feed will be about your teen’s activity, since they have the only account you follow.

3. If you have access to your teen’s account, log in as them, and click the hamburger (3 parallel lines) at top right, click the gear at bottom, then click accounts > Posts You’ve Liked (I know this is so buried!) and you’ll see all posts that have been liked by “your” account.

4. You can set up an IFTTT recipe if one is available or if not, see if someone can create one for you. https://ifttt.com/instagram

I’m open to other options but right now I don’t believe you can be notified if someone else takes actions, other than posting.