Tenant subleasing and paying min rent

[Bela B.]

I have a tenant who has not lost her job (professor at a private university), is paying the min 25% rent and is subleasing (property is in LA County). It is stated in the lease agreement she cannot sublease but she consistently is (neighbor has told us there is a consistent revolving door of people in and out). I live in SF so I cannot just show up and see who is there. My lawyer needs proof to move forward with eviction for just cause. How can I get proof? I check Airbnb/Craigs list/Westside Rentals constantly to see if the property is listed. ALSO, I just served her the AB 1482 exemption which is technically late (due by Sept 1), will this hurt my chances of eviction even if it is for just cause (subleasing).