Can we just clarify the terminology first? When you say 'User Profile', do you mean User Account?
When the PC boots, do you get the option to logon as (say) Mr Maj or Mrs Maj? If you go to Control Panel > Accounts, do you see two separate Accounts - one for you and one for your wife?
If so, there is no simple way for her to view the contents of your Inbox from within her Account. She would need to go to Start > Log Off > Switch User, choose your Account, then view your Inbox.
When she has done, she would then choose Start > Log Off > Log Off to close your account, and return to her screen exactly as she left it.
I'm sorry if this Accounts vs Profile thing seems pedantic, but there is a Profile Assistant within Outlook Express (to remember your personal details and post them to an web page that asks for your personal information). I just wanted to clarify that we are talking about the same thing :)