She's not really a musician, so she wouldn't have a home page like others do.
But, I think the best thing to do would be check the way back machine to see what that site used to be. Because she did not always have a makeup line. It is possible that her "official" webpage became her makeup webpage.
My "vote" -
In general, I would not want to see a bunch of marketing sites being added. But if a non-musician's home page points to something that they are known for (KVD makeup as example), I would be ok with that.
The link on her page gets redirected to the makeup page. Kat von d dot net was her site, but it now automatically opens Kat von d beauty dot com