I thought they may be upset, but that text really meant so much to me. 

If they act very upset then maybe offer them a small credit to next month's rent.

She has no viable reason to kick me out, but she’s upset that I left a light on and she argued with me about it one night through a text conversation, so she’s still upset about that.

Unless this is within your family and you won’t be upset if there is a $30k lien “no one knew about” or you won’t be upset if it turns out they didn’t really have title. 

Apparently it was really upset about the move.

I notified the tenants, now she is very upset and googling tenant rights.

They revel in trying to get you upset especially about something that appears to be trivial and enjoy making you appear unreasonable especially if it enhances their 'victimhood'.

I caught myself getting upset with them when speaking to them which probably made them upset too. 

If I had, it might have put a bad taste in my mouth, upset my wife, and caused me to give up/ quit before realizing/receiving the benefits of landlording.

Encourage the buyer to investigate if you aren't sure and they aren't sureDon't hard sell or try to put a buyer in a property that you don't think they will be successful withDon't get upset with people, even if they are yelling at you.