Timothy Olyphant's daughter Vivian

Why is she not listed in IMDB's database as Timothy Olyphant's daughter?  Despite it is WELL known, she is his daughter?  is that a by choice or something by IMDB?  Just google her name and you will see all the confirmation you need.

What is REALLY drawing attention to this is her role in Tim Olyphant's newest Show Justified: City Prime Evil, where she herself plays the role of his characters daughter, not only in the show, but as his actual daughter.   Nepotism be damned.   She is doing a good job. 


EDIT:
Sorry y'all, I did not convey the message properly:

Look at Tim's page  https://www.imdb.com/name/nm0648249

Scroll down to "Personal Details"  specifically under Children:  Where is Vivian's name? Grace is there, why is Vivian's not?