Enviar, receber e organizar e-mails no Outlook.com
Hi, I'm Julian. The best option to do is to try Microsoft Account Recovery https://account.live.com/acsr. Make sure she enters the exact email addresses and fills in as much detail as possible.
Please refer to this guide for help. https://support.microsoft.com/en-gb/account-billing/help-with-the-microsoft-account-recovery-form-b19c02d1-a782-dee6-93c3-dc8113b20c42.
Has your wife recently changed her phone number, recovery email, or security settings? That could explain why none of the sign-in methods are being accepted.