User account is not accessible for login, but remains in Users folder. Can it be re-activated?

My 18 mo old grandson hit a few keys on my wife's mid 2010 MbPro while she was logged in and eliminated her user login from the startup/login screen. I used resetpassword utility to reset p/w for System Administrator to access the machine and the user folder is intact. (The account also does not appear in the resetpassword pulldown list of users.) I have copied all of the folders except Library in her original account into a newly created account. Is there a procedure to (1) re-activate/re-access her original account, or (2) migrate her original Library information/settings to the new account?