My response:
You need to give her 30 days written notice. If she fails or refuses to leave upon that expiration date, then you'll need to file an action for Unlawful Detainer.
Here's a sample notice to use - -
30-DAY NOTICE TO TERMINATE
TO: ....................
ADDRESS: .............................. (rental premises address)
PLEASE TAKE NOTICE that your month-to-month (or other periodic) tenancy of the above-described premises is hereby terminated as of the date .......... [thirty (30)] days after service of this NOTICE upon you and you are hereby required to quit and surrender possession of the premises to the undersigned no later than .......... [thirty (30)] days after service of this NOTICE upon you.
This NOTICE is intended as a .......... [thirty (30)] day legal notice for the purpose of terminating your tenancy in accordance with California Civil Code Section 1946 and 1946.1 [and .......... (applicable Rent Control Ordinance, if any)].
This NOTICE OF TERMINATION is served upon you for the reason(s) checked below:
___ In jurisdictions not subject to local rent/eviction controls,
landlords generally need not state a reason for serving a 30-day
notice, although specification (and proof at trial) of a "good faith"
reason may avoid a successful retaliatory eviction or unlawful
discrimination defense. Most rent control jurisdictions, on the other
hand, require that the 30/60-day notice state a "good faith" reason for
eviction; and some rent control jurisdictions authorize a 30-day
notice eviction only for grounds specifically authorized by the
governing ordinance.
___ Committing or permitting to exist a nuisance in or causing damage to the above premises or to the appurtenances thereto, or to the common area of the complex containing the subject rental unit, or creating an unreasonable interference with the comfort, safety or enjoyment of any of the other residents at the same or any adjacent building.
___ Using the rental unit for an illegal purpose.
___ Refusing the landlord reasonable access to the rental unit for the
purpose of making repairs or improvements, inspection as permitted or
required by the renatl agreement/lease or by law, or showing the same
to any prospective purchaser or mortgagee.
___ The landlord seeks in good faith to recover possession of the rental unit for use and occupancy by the landlord or the landlord's spouse, children, parents, grandparents or grandchildren.
___ The landlord seeks in good faith to recover possession in order to
demolish or perform other work costing not less than $5,000 and
necessitating the removal of the rental housing use for not less than
25 days.
___ The landlord seeks in good faith to recover possession in order to
permanently remove the rental building from residential rental use.
___ We just don't like you.
The date, place, witnesses, and circumstances concerning the above are as
follows: ______________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
DATED: ............................ ___________________________________
(Landlord or Landlord's agent)