emei

Type in the id and password of the account that it's locked to.

If you can't remember your id : If you forgot your Apple ID - Apple Support 

Or, and if you bough the iPhone new (i.e. it’s not second-hand), you could try going to an Apple Store (make a Genius Bar appointment if you do) or try contacting iTunes Support online (https://www.apple.com/emea/support/itunes/contact.html) and see if they can remove the phone from the account - they are likely to want to see proof of ownership before they might help e.g. original receipt with the serial number on it

If she is the original owner, she can take the device, the original purchase receipt with the serial number, and a photo ID to the nearest Apple Store.

Genius Bar Reservation US

or contact Apple ID Support. They will need to see the original purchase receipt/paperwork also.

Apple ID Support

Apple ID Support (2) 

Apple Support by e-mail or chat         Select your device, Battery, Power and Charging, then Power adapter not working to get a chat option. 

Apple Support using Twitter

Or fill out and submit this form.

How is the phone locked ? If activation you don't send the IMEI number, you can do : Turn off Find My iPhone Activation Lock - Apple Support

She should do what I posted in my previous reply