Tenant vacated property without notice

[Tom McGee]

I just had a tenant vacate without notice in PA. She is on a one year lease until April 2025. Two weeks ago, she sent a request to leave and I prepared an agreement so I could acquire a new tenant first. She never responded. 

Today she moved out and vacated the property. I sent communication but it has not been responded to.

Can anyone provide advice:

What are my legal rights?

At what point can I begin to market the property and find a new tenant?

am I legally allowed to keep her last months rent and security deposit?

Is there a legal letter I should send?

What should I be proactive about?  Things to avoid?

Looking for some advice. 

[Theresa Harris]

Quote from @Tom McGee:

All good points! 

She did not say a word. The neighbors told me she left. I visited the property and the place is cleared out. The key was left.

I am relieved she’s gone. I just want to make sure I don’t make a mistake by listing it without having anything in writing. And I have her last months rent and security deposit. 

Again, she signed a one year lease just 3 months ago. 

 As she left the key, post notice that you are entering the property in 24 hours to confirm what you were told by the neighbours as well as her message from XXX day.  Ask her to please reply to confirm that she's vacated the unit so you can find a new tenant.  Check the utilities have been moved out of her name and if they have, she left the key, you have it in writing that she wanted to leave and all of her stuff is gone, then I'd say go in and start getting it ready for the next tenant.