Karyuu,
the question's about parents name. Your confusing it now with profession, I think.
I'm talking with the risk of not having created a new char as to test this, but just from what I can recall, but I'd say that parents names never show in char description (that shows profession of each other) and Nukl, what you've been told is true, just don't worry much about it, anyway, remember that you pick up your char name first, even you can put a surname there, and then at the parents screen, that surname will not appear appended to any of them.
Truth is that parents name really doesn't matter at all, and you can roleplay being an in game brother with your RL brother perfectly, you just agree to it, and agree to who your parents were and their names. You just have then to keep that in mind and RP accordingly.