Laws for landlord/tenant are very state specific, however typically the tenant doesn't pay when the property isn't habitable (this situation) and can either breach the lease or sue for damages when the property cannot be inhabited for more than a few days (I think it's 5 in my state). 

Mold needs moisture to grow.Look in the lease for inhabitable conditions clause to see if you can terminate the lease based on that. 

The property must be kept in habitable condition and the S8 office will send an inspector out periodically to make sure it is.

Our lease has language that it cancels if not inhabitable.

If a hurricane makes property un inhabitable, does LL have to pay for tenant to stay in a hotel?

., & though Common Law continues to be added to, as well as, does change; as far as I know, Common Law is yet to decree what will be decided between the inhabitants of a Rental, & even for some of the inhabitants have left the Rental, while some inhabitants continue to live in a Rental.

As much as this is a business, apartments are inhabited by people, and if they feel like they don't matter to you except as a number, and the place is not spectacular, and they can get just as good elsewhere, they will go.

If you do a corporate rental, you have no control over the actual people inhabiting the unit.  

So, any 30 day notice after their lease expired wouldn't be valid.My opinion as to her claims for inhabitability, is that she's got no claim there.But, the good news is, that if she hasn't paid rent, you can still file eviction for nonpayment of rent.  

A realtor noted that in California, the inhabitants have one month of "buffer" for each year they've lived on the premises.