Find My app doesn't work for me.

Hi, I am trying to set up the Find My app on my iPhone 7 plus so that my wife and I can locate each other. My wife's phone is an iPhone 7 and is set up ok and she can locate me on her phone but when I try to locate her on my phone I get the "can't locate" message.

We are on the same network and pretty much have our phones set up the same for locating a friend. I'm the only one listed on hers and she is the only one listed on mine.

I must be missing something, I've googled similar problems and followed the advice offered there but still can't get it to work.

Any suggestions would be appreciated.

Thanks