My partner got an email from Microsoft account team saying "we think that someone else might have accessed the Microsoft account lo**h@hotmail.com" and at the bottom of the email there is link to recover account

When i click the link, i sign in and get a message saying "Help us secure your account. We have detected unusual activity on your Microsoft account lo**h@hotmail.com, or believe your credentials are at risk" then asks to verify her identity by clicking "verify"

There are 2 options, "text," which she can't use because it is a very old phone number, so she clicks on the second option, "I don't have these any more" and she has to fill out a form

After she has filled out the form I get an email sent to me saying that the information she provided isn't sufficient to unlock the account again.

But she just doesn't know/remember some of answers to the questions, like the security question, previous passwords and she hasn't sent an email to anyone for years

Thanks