Need help with recovering account with barely any details

Hello, I need help with recovering my Mothers Microsoft account since my Brother and I need the account to log back into Xbox Live since it's the parental account for it. We've tried to recover the password through the filling out of the forms but since my mother didn't use any credit cards or actually use the account for email we can't fill the details for that. She also had forgotten the security question answer and so we're at a stand still for the moment since we can fill out the basic information but that's not enough apparently.Also we don't know what email address gets the recovery password (most likely another old account which we've forgotten about !).Strangely enough we have access to the actual email (which is Blue-yonder) though Virgin Media  but it's a different password to this Microsoft account. I know that this is inconvenient but is there anyway for the recovery password to be sent to the actual Blue-Yonder email or anything as easy as that ? We can detail the Xbox Live accounts linked to the Microsoft account and I have a general idea of what the password is (we remember 1 word of it we think).Also if this is in the wrong place sorry !