Ipad with invalid/unsupported Apple ID?

[Jakob Rosengreen]

Hi
Is there any way I can disable Find my iPad on my sister's old iPad?
She doesn't know the password
I keep getting the message that the Apple ID is invalid and/or unsupported
Thanks in advance

 

[J. A.]

Welcome to iPad Forums!

If she doesn’t know the password, you can’t remove it from Find my iPad.

Try resetting the password:
If you forgot your Apple ID password

If that doesn’t work, Apple might be able to help.
Visit the next Apple Retail Store and take the billing with you, so that your sister can prove she’s the owner.