How to recover Apple Account and unlock MacBook with forgotten login credentials?

Hey everyone,

I need some help with my sister’s MacBook. A year ago, when I was an exchange student in the U.S., I bought a MacBook as a gift for her. The problem is, she didn’t use it for an entire year, and now she has forgotten everything—her Apple ID login, password, the email linked to the account, and even the MacBook’s lock screen password.

We are currently in Kazakhstan, and I’m wondering if there’s any way to recover her Apple ID or unlock the device. Has anyone been in a similar situation? Any advice would be greatly appreciated!

Thanks in advance!

[Re-Titled by Moderator]