@Cassie Kwok,
**No good deed goes unpunished!**
There are points about not considering them tenants, but not sure if that will fly.. (will they leave voluntarily after having an honest conversation with them? Will you evict them if you have to? @Robert Marston makes a good point about tenancy. No written lease means nothing. No rent payment is up to interpretation. And this is Oakland.. But I disagree regarding the Cap-ex pass-through, when you are more likely exempt from rent control..
1) Rent Control
As @Account Closed said, it's most likely exempt from rent control if it's a single family home. However, it may not be exempt from Just Cause. So be careful about just giving notice. I agree, check with attorney.
Here are the exemptions from the City of Oakland Rent Adjustment Program.
http://rapwp.oaklandnet.com/issues/exemptions/
You should also file for a Certificate of Exemption from rent control with the city of Oakland to confirm. And that will you save you some time if push comes to shove.
You can download the Property Owner Petition for Certificate of Exemption here:
http://rapwp.oaklandnet.com/petition-forms/
If you are not under rent control, CA law requires 60 days' notice for increases in rent over 10%. After that, is in effect. If the rent is then unpaid, you have just cause for eviction, and can move forward.
2) Just Cause Eviction
The person may still be protected by "Just Cause Eviction," even if they are not under rent control.
See legal advice. I am not a lawyer. I don't nuttin about nuttin..
3) Don't want do deal with it?
Cassie, if you end up going the long and hard route and don't want to deal with your family in that way, you can also hire a lawyer or service to do the eviction. Or you can sell the property at a discount, and let someone else deal with it. (I'll make you an offer if you want to sell it). I think you can deal with it yourself, but it's really a matter of perseverance and pain endurance - depending on your relationship and feelings towards them..