It sounds like your wife may have a less reliable / Slightly dodgy GPS unit in the Phone.

That blue circle you are probably referring to is saying "Your wife is somewhere within that blue circle". It is having problems trying to track the exact spot backed up by the fact she is like 2 blocks away.

As you have no blue circle , it is showing it has pinpointed your location showing your GPS is working effectively. Maybe your wife should consider an replacement handset?

Carl

 

The blue circle indicates margin of error. I often see my location on the map as one neighborhood over, but the blue circle just barely encloses my actual location!

I have found that the GPS doesn't work as well for me if I turn it on and off to try to conserve battery power. I have begun leaving it on all the time. I also do not use the wi-fi signal as a means of determining location. When that option is also checked in my settings, it seems to cause the blue circle to grow.

Finally, when you compare the two phones side-by side, where were the two of them in the previous half hour or so? My GPS seems to have a harder time pinpointing my actual location if I've been indoors for an extended time, or if I have been moving around since my last GPS-necessary app was last used.

 

You might also check to make sure GPS is actually turned on. It will try to locate you with a blue circle based on the cell tower you're closest to if your gps is turned off. I was confused when I first got the phone because gps was off by default. Once I turned gps on though, it was very accurate.