How do I get my sister's Minecraft account back

Hello,

If I am reading this correctly. You do not have:

• Password
  
• Email - and access to the email that is set as your sister's email? You created a burner email and do not have access to that either?
  
• The account has no linked email's or phone numbers either.
  

Things that I am assuming:

• You purchased Minecraft on the corresponding Microsoft Account you do not have access to?
  
• She is not attached to a Family account setting of any kind - It is just an independent Microsoft account.
  

If you could clarify what you do have for the account that would make it easier to give you a concrete answer. I can say with confidence that if you do not have the email or access to the email with no security or back up features - the account cannot be recovered. Otherwise you can try contacting Microsoft Support via your account, or if you have the email you can try adding her to your family account but without at minimum email and access to it.

If these accounts are linked you can try unlinking by contacting Mojang: Minecraft for PlayStation® 4 FAQ – Home

Linking a Microsoft account to a Playstation 4® account:

WARNING Once a Microsoft account has been linked to a PlayStation 4® account, neither the Microsoft account nor the PlayStation™ Network account can be associated with a different account. 

If you choose to unlink accounts, then purchases will be returned to the account which made the purchase. Even after unlinking, Microsoft and PlayStation 4® accounts can only be re-linked to the original account.

If you believe that your Microsoft account or PlayStation™ Network account have been linked incorrectly, then please contact Minecraft support.

Best Regards,

Thank you for your consideration but I tried to contact the Xbox support and I can't find a good way to describe the problem. I also tried to contact the virtual agent but it cannot deal with the problem that I have.

I would but I have no idea what Microsoft account he linked it to, so all I really know is the old minecraft.net account information like the email, username, and password.

Have you already contacted Brayden K support? I'm waiting for your response!

I appreciate your efforts. I suggest that you keep trying to recover it from there. Check the link below for more tips about the recovery form.
https://support.microsoft.com/account-billing/h...

Alternatively, try to reach out to Xbox Support here:
https://support.xbox.com/en-US/contact-us