Locked iPad

I have had me iPad for many years now. It was a Christmas gift around 6 years ago, a couple years back my younger brother was playing around with my iPhone and selected my iPad was stolen.For years it has been locked due to this. I cannot remember the Apple ID password due to it being years old I have created a new one, the email address is also very old. The only way I can prove it Is mine is by the name on the email. I have asked my mum if she has any proof of purchase however due to it being years old she does not have this.

Any advice or support you can give me on this would be very good as I would love to be able to use it again and access my old photo's.

Many thanks and best wishes,

Courtney Clark.