I'm 19 and currently working earning well thankfully.
I would prefer to share the account especially once we've got a house however if she doesn't want to I'd still give her access to my account because why wouldn't you trust the person your getting married to and hopefully spending the rest of your life with,
I mean I currently have an account in my name but let my mum look after my money so i invest in the correct places.
All about the individual and how much you trust them.