Why does FaceTime ring on all my devices? Have tried everything! when my daughter receives a FaceTime call from one of her friends (now that I think about it it may be only this one friend), my iPhone, my husband's iPhone, and my iPad all ring.  I set up separate iCloud accounts for all of us and turned off cellular calling on my iPad. There doesn't seem to be an option to do this on the iPhone any longer. Despite these efforts,  all of our devices still ring when my daughter gets a FaceTime call from her friend. What should I do next?
It sounds like you have the same AppleID on all the devices. The default is that all devices configured with the same AppleID use the primary email address associated with that Apple ID. 

You have a couple of options:


Use a different AppleID
Use a different email other than the primary one.  There's an excellent article on how to do this workaround 


Basically, you go into the Facetime settings on on each device you don't want to ring and add another (different) email.