With the info you've shared, I'm in the camp of giving them notice that you are ending their tenancy at the end of the lease.If you are not going to hire a local PM, see if you can distance yourself a bit emotionally - sounds like they have gotten under your skin if they have damaged your property and what really bugs you is their asking for their check back.  

If you don't know the buyers personally (enough so you can call and ask questions) strongly consider taking another directionFriends don't let friends do bad deals, listen we all want warm fuzzes when working with people but the reality is, your running a business. protect your self at all time - its not personal its business. be objective (AND THIS IS HARD) but houses, don't have feelings, wholesale fee's don't have feelings, title company stamps and legal paperwork have no feelings, if your the feely type get a hobby or pour your emotions in another venue. real estate (demands) you to be at the wheel, and be ready to face the ugly truth."

Never buy a property based on emotion.

Robert Kiyosaki four years ago; His book Rich Dad Poor Dad made an emotional impact on me.

(Emotion has no hold in court, so fighting summons)

She's emotionally drained right now from this property or dealing with the bank or whatever lead to her falling behind.

Loving it too much will hinder your better judgment and cause emotional distress.This is a business of evictions, damages, repairs, and doing it all over again. 

You will need to emotionally detach and see it as a rental.

If the answer is no, just get a rental you're not emotionally attached to.There are good renters out there, and a $240k (gulp, flinch) rental house will usually appeal to a higher class of tenants.  

We have a widowed female that could be a emotional roller coaster.