Q: How dose my wife get the music we have on iCloud onto her new iPhone 6

Hi nigelfromgillingham,

Welcome to the Apple Support Communities!

From your question, it sounds like you have purchases on your iTunes Store account and have set up Family Sharing with your wife so that she could have access to those same purchases. If this is the case and you are trying to download this content on her device, please use the Download content from family members section in the attached article as a reference for completing this process. 

Sharing purchased content with Family Sharing - Apple Support

Best regards