Please be aware that Snapchat has just had a huge update. It now shows where any of the user's (your child's) friends are at any time. It uses GPS to precisely pinpoint on a map where the users are, even changing to a car when they move quickly. Your child and other users are depicted by a Bitmoji.
Once you get onto the Snap Map it'll show you where your Snapchat friends are and what they are doing there if they share a picture. The update also allows you to upload Snaps to the "Our Story" so that anyone can see your picture.
Don't worry though - if you don't want your location shared then you can set up a "Ghost Mode" to keep it private (see instructions for this below).
It may sound like innocent fun but if your children have their location shared then people can potentially track them down. If you zoom in enough on the map it shows you exactly where someone is such as their house!
The map shows exactly where they are which has raised serious concerns. While they would need to know your child's username, and for them to accept their friend request, to access this information it is often easy to find it online.
Update: To turn on Ghost Mode: Open Snapchat onto the camera screen. Pinch inward on this screen as if you're trying to make it smaller.
You'll then be taken to the map screen.
You will see your Bitmoji, (or your green silhouette) click on it and your settings appear at the bottom of the screen. Click there and turn 'ghost mode' on.
If you haven't done the update yet (as from 21st June), ghost mode won't be available.