Tessitura Naming Issues

As it occasionally happens, one of our users got married.  She has also become a solicitor, which necessitated the appropriate change in the Tessitura Security module from USER to BOTH.  However, it occurs to me that someone will soon call to say "Hey, can we change her last name too?"  Being a database guy, I figured there are likely greater implications at work here, so I'm posing this question to you all.  Can I just change the user login (from MFORD to MHAYS) and last name in the security module to reflect her new status or will Tessitura freak out?  I suspect it's not that easy...

Thank you in advance, Tessiturians.

BONUS NAME-RELATED TRIVIA:   The Comte de la Fere, the Baron du Vallon, and the Chevalier d'Herblay are better known in literature as The Three Musketeers.