Ask HN: Hotmail password recovery using landline

I am assisting in recovering the password of an elderly woman's hotmail account. She is still signed in to the Outlook app on her Android phone, and has access to the phone set up as the recovery phone number. However, this phone number is a landline and outlook.com will only send text messages for verification, which she is unable to receive. Trying to regain access by answering questions about recently sent and received emails also failed, even though all entered info, such as subjects and recipients of recently sent emails, was correct. What other options would be left besides creating a new account/address?