I often use Find My Friends to keep track of the kids. I presume its location methodology is similar to Find My iPhone. Here's how it behaves:

About 10% of the time, it doesn't show a current location at all for the kid. It does remember the previous one, so it will show a location and say something like "46 minutes ago".

When it does display a location, about 60% of the time it's a single spot.

The remaining 30% of the time it is a spot enclosed by a tinted circle. That circle can be a few hundred feet in diameter, or it can be more than 5 miles in diameter. This is the potential error. However, I'd bet that 95% of the people looking at it don't understand the concept of "potential error". So to them, the enclosing circle doesn't exist.

Edit: forgot to add, about 2% of the time it will show an "exact" location, what I called a "spot", no "potential error" circle. Then a minute later it will show a different exact location a few miles away. Then a minute later yet a third exact location another mile or two away. So in other words, about 2% of the time it is really confused (the kid is stationary the whole time).