I would rather my girlfriend have no say in the hiring of my new assistant.
Why would it work out better if she did not have a say?
She would try to make sure it was someone she liked.
I can understand that. Really, your girlfriend shouldn't have anything to do with what you do at work.
It's not a relationship, I'm worried she'll follow me around and make me do stuff I don't want to do.
Well your partner should understand that you need to pick an assistant that is right for you and your line of work. While it would be nice for you to respect whatever opinion she has, just let her know that the final decision is yours in this case.