Activation lock ipad air 2 no access to email and phone number

In the absence of the original purchase documents your only way forward is to attempts to retrieve the ID and reset its password by going to http://iforgot.apple.com . If this fails try going to https://getsupport.apple.com . Click' See all products and services', then 'More', then 'iCloud', then 'Account and Setup', then 'Troubleshooting iCloud account issues'. Then click 'No thanks. Continue' to be offered contact methods. Note that while Apple may be able to help you retrieve the ID (it will need to be the person who created it who does this) they will not unlock the device for you without the original purchase documents and the verified presence of the original purchaser.

She may be able to retrieve the ID and reset the password using the link I gave you, then she can tell you them. Support may be able to help her retrieve the ID if she has problems: but for Apple actually to unlock the device she would have to take it to an actual Apple Store together with the original purchase documents and some ID.

The grandmother needs to be the one who contacts Apple ID Support since she set up the Apple ID.

You are welcome. The Apple Store is most likely going to want to see the original purchase receipt.