Can't figure out how to so I can login with my win account
Have you tried simply going to Settings -> Accounts -> Left Column (Email & Accounts) and selecting "Add a Microsoft account"?
And will desktop same the same with same apps?
IF by "same" you mean, the same as the former desktop of the former account, then No.
A new account builds a new profile and with that new profile comes a new desktop.
IF you've been syncing "your" Microsoft account, then many of your settings will come along with that.
AND
Most if not all of the previous applications that have been installed will not be changed, although you may have to do some "Pinning" here and there to get things as you would like them.
Make sure that when you add the account that you ensure it's a member of the local administrator's group.
OR
Promote it from Standard user to Administrator using her old account.