I'll make this as brief as I can.

My mother has been living in her apartment for something like 12 years. Her original lease says nothing about smoking in her apartment although it does say no smoking in public areas.

She received a notice on her door today, taped to it and no email or any other correspondence to go along with it, saying that her lease will be modified, effective 30 days of the notice, today, the 5th.

If she hasn't agreed or negotiated or literally had any conversation with the management company, is this enforceable? I understand there's a lot in California state law that I don't understand. I guess the other way to phrase the question is that from the day she moved in, nobody ever said anything about smoking in her apartment. None of her neighbors have complained, and again, this is 12 yeras in.

Any suggestions or adivce are more than appreciated.