Can my landlord restrict overnight guests if there was no guest policy discussed in the lease?

I am renting a private studio apartment in the basement of a house where the landlord lives in the main house. I have a private entrance and no shared common areas. My lease agreement is very basic and does not have a guest policy. My landlord is not happy I have an overnight guest approximately 10 nights a month - maximum of 3-4 consecutive nights at a time. I offered to help with the increased utilities (my landlord pays for all utilities) but landlord asked that I pay 10 dollars per night for overnight guest. I am unsure if I am considered a lodger in this situation. I am concerned my landlord can restrict overnight guests if I refuse to pay the additional money she is asking for. When does a guest become a occupant in CA?