I'm trying to see which email the confirmation goes to

Unfortunately you can NOT see which code was used on which email.

Try to remember which emails you used in the past, and sign into those old emails for purchase confirmations and the likes.

Also try Forgot the Microsoft Account Email Address for your Xbox Live account? Learn How to Find It.

Hi and thanks for reaching Microsoft Xbox gamer's community. My name is Josef.
I'm an Independent Advisor and a Microsoft Xbox user like you.

Hope you're doing great today Igor

Do you received the confirmation email address in the account that you are trying to use to sign in minecraft?

In case you have more than one email, please try checking on each one (and use the sign in with Microsoft button) to see how it goes

I'll be waiting for your reply

I'm not sure "*** Die E-Mail-Adresse wurde aus Datenschutzgründen entfernt. ***" is a real email address, but I'm trying to DM the Ambassador Twitter account, so we'll see how that goes. Thanks for the help.

Another thing that came to my mind that you can try is:

If you had order confirmation emails about these purchases, you can try contact Microsoft support and see if they can honor the price based on these confirmation emails

Hey Caden!

Nice to meet you! I'm Darhyl, an Independent Advisor. I'm sorry you are experiencing this. I am here to help.

I just want to confirm when you are trying to access your mother's email address for Shorty122006, it directs you to your other account, is that correct?

To confirm this, you can try to sign in to your mother's email address on account.xbox.com, and from there check if you will see the gamer tag "Shorty122006" on the right top corner of the page.

Please let me know the results once you're done.