Managing personal Outlook.com account settings, security, and privacy
Hi again @Steven Schlichte apologies for providing you with the wrong information earlier, you don't need to contact Microsoft Support for further assistance with your mother's account.
If you don't have full access to your mother's account, unfortunately there's no way to recover it. If you're locked out of your Microsoft account because it is connected to your account, unfortunately the only way forward is to fill out the account recovery form: https://account.live.com/acsr
Microsoft Account Recovery form is currently the only official way to recover your account. You can try it up to twice a day.
If it’s already been a few weeks, you can check this page: "Account recovery unsuccessful" https://support.microsoft.com/account-billing/account-recovery-unsuccessful-dc56c3e3-dff0-4ed5-8edb-60290eea6b53 it includes extra tips from Microsoft that could improve your chances.