How to determine an abandoned property?

[Sergii Pyrog]

Hello.

I have rental property in Houston, TX and have an issue with my tenant. Tenant did not pay rent on 1st of the month (she always paid 1-2 days in advance). She does not reply to messages and her phone is off. I went online and on her facebook page she has a post: "Selling furniture. Urgent" from last week. I asked neighbor and he told me that he did not see her car for past week. I went to the apartment and saw that the door was not locked and the key from the unit was inside. She still has furniture, but no clothes. My lease agreement states: 

"Abandonment" occurs when all of the following occur:

(a) all occupants have vacated the Premises, in Landlord's reasonable judgment; 

(b) Tenant is in breach of this lease by not timely paying rent; and

(c) Landlord has delivered written notice to Tenant, by affixing it to the inside of the main entry door or if Landlord is prevented from entering the Premises, by affixing it to the outside of the main entry door, stating that Landlord considers the Premises abandoned, and Tenant fails to respond to the affixed notice by the time required in the notice, which will not be less than 2 days from the date the notice is affixed to the main entry door.

I know its early to worry, but if I does not hear from tenant in the next 3 days can I treat the property as abandoned and serve the notice? What should I do with tenant's furniture? Or is it better to file for eviction?