Rent 9 days late - Tenants gone! Texas

[Anthony Varner]

Hey there, anyone who can help, thanks in advance.   

My tenant is late 9 days and I haven't seen anyone there in a while.  It's a duplex - I'm upstairs, they were downstairs.  The thing is - she told me they were having issues with bedbugs (and then roaches too).  So she was going to throw out the mattresses, sofa, linens, etc., then have the place cleaned/exterminated, before moving back in.  I've asked about payment when it got late and she said she would pay, then didn't pay.  Same thing a couple days later.  I posted the 3-day notice to pay or quit after 6-days late.  Right now is day 3 since the notice posted.     

Does anyone here know the proper way to proceed with this?  I know she just wants to abandon the place rather than stick to the plan.  This is of course breaking the lease but this wouldn't exactly be an eviction case since they are no longer there, right?  

Do I need to get something in writing from her saying that she is not coming back?  Or after today if there's no response and no payment still, am i allowed to simply take back the property?  This is for Houston, TX.

I'm okay with them leaving - i just want to make sure this is handled exactly right.  Want to get in there right away, exterminate, clean, and re-rent it out.  Also I want to make sure this is reported and affects her credit.  

Thanks BP

-Anthony