User last name changed, now cannot unlock locked computer with that username even though she logs in initially with it successfully

We had a user get married and we changed her last name in AD (2012 Std).  We use first initial last name.  Now when she logs in, her workstation (W7 Pro 32) accepts her new username, but when the computer is locked and she goes to log back in, even though it shows the correct first initial and last name is the one who locked it, it will not accept her logging back in, she has to do Switch User and put in her old first initial last name with her correct password to get back in.  I have researched this online and found others have had the situation where the lock screen would not unlock using their username and password, even when their name had not changed, and they would have to reboot and get to a login screen to be able to get in, but no one seems to have an answer.  Anyone?

05/22/18 For some reason I am unable to post a Comment - click the link and nothing happens - but this user is being given a new PC, so this has become a moot point.  I appreciate your responses.