IPhone 6

Make sure your friend did all this:

What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support

The only way to remove the ID is to use a way that requires entering that ID, whether it be through iCloud.com, on the device itself, or perhaps some other way. The only ones who can do this without that information are Apple and they will only do it with very strict ownership demonstration that your friend would have to provide to meet their requirements.

Do this online at: Activation Lock support request - https://al-support.apple.com/#/additional-support Apple says, "Proof of ownership documentation is required," but does not state what currently constitutes proof. Prior to this new online service Apple typically required the original receipt issued by Apple or an Apple Authorized Reseller and documented provenance (so typically it would be the original owner who does this, or a descendant with legal proof of ownership).

Restoring it using iTunes won't turn off Find My Phone. Can you get her to do the steps in the link Limnos posted?