Yes, if she has vacated the premises you can change your locks. As for her belongings, you have to follow statutory procedure as outlined below under Florida law.
715.104 Notification of former tenant of personal property
remaining on premises after tenancy has terminated.—
(1) When personal property remains on the premises after a tenancy has terminated or expired and the premises have been vacated by the tenant, through eviction or otherwise, the landlord shall give written notice to such tenant and to any other person the landlord reasonably believes to be the owner of the property.
(2) The notice shall describe the property in a manner reasonably adequate to permit the owner of the property to identify it. The notice may describe all or a portion of the property, but the limitation of liability provided by s. 715.11 does not protect the landlord from any liability arising from the disposition of property not described in the notice, except that a trunk, valise, box, or other container which is locked, fastened, or tied in a manner which deters immediate access to its contents may be described as such without describing its contents. The notice shall advise the person to be notified that reasonable costs of storage may be charged before the property is returned, and the notice shall state where the property may be claimed and the date before which the claim must be made. The date specified in the notice shall be a date not fewer than 10 days after the notice is personally delivered or, if mailed, not fewer than 15 days after the notice is deposited in the mail.
(3) The notice shall be personally delivered or sent by first-class mail, postage prepaid, to the person to be notified at her or his last known address and, if there is reason to believe that the notice sent to that address will not be received by that person, also delivered or sent to such other address, if any, known to the landlord where such person may reasonably be expected to receive the notice.
History.—s. 11, ch. 83-151; s. 842, ch. 97-102.
715.105 Form of notice concerning abandoned property to former tenant.—
(1) A notice to the former tenant which is in substantially the following form satisfies the requirements of s. 715.104:
Notice of Right to Reclaim Abandoned Property
To: (Name of former tenant)
(Address of former tenant)
When you vacated the premises at (address of premises, including room or apartment number, if any) , the following personal property remained: (insert description of personal property) .
You may claim this property at (address where property may be claimed) .
Unless you pay the reasonable costs of storage and advertising, if any, for all the above-described property and take possession of the property which you claim, not later than (insert date not fewer than 10 days after notice is personally delivered or, if mailed, not fewer than 15 days after notice is deposited in the mail) , this property may be disposed of pursuant to s. 715.109.
(Insert here the statement required by subsection (2))
Dated: (Signature of landlord)
(Type or print name of landlord)
(2) The notice set forth in subsection (1) shall also contain one of the following statements:
(a) “If you fail to reclaim the property, it will be sold at a public sale after notice of the sale has been given by publication. You have the right to bid on the property at this sale. After the property is sold and the costs of storage, advertising, and sale are deducted, the remaining money will be paid over to the county. You may claim the remaining money at any time within 1 year after the county receives the money.”
(b) “Because this property is believed to be worth less than $500, it may be kept, sold, or destroyed without further notice if you fail to reclaim it within the time indicated above.”
History.—s. 11, ch. 83-151; s. 3, ch. 2001-179.