We each have to do it our own way. I have had my difficult child daughter call me from jail. And you are right, it is VERY expensive. This has happened to us a couple of times, and it was very upsetting for me and my husband. Not only to hear the fear, the plea's, the lie's etc. it just kills a parent to know your child is in jail! That's where the detaching that Star mentioned comes in. YOU have to remove the emotion from the situation. The times I did take the (expensive) phone calls from jail, I removed myself emotionally from the conversation. I first told my daughter that I couldn't stay on the phone long and that 15 min. was all I could afford. Not necessarily true, but I made an on the spot "executive decision" that our budget would only allow 15 mins. jail long distance. I was pleasant and listened. She has never followed our advice, nor was she looking for any. She basically wanted to talk and talk and talk and talk about how wronged she was. No amount of reasoning or arguing would have made a difference, so I chose to say a lot of....... oh, really, hmmmmmm, oh my goodness, I wish things were different, my,my,my! Things like that. I neither agreed with her nor did I disagree with her. THAT WORKS! At the end of the conversation, I could tell her I loved her, to take care and that I hope things work out for the good of everyone. That seemed to be helpful to her and kept me from projecting my feelings onto her and best of all, she thinks our relationship is sooooo much better now.
That's pretty much how I deal with her now in everyday life. Everything is just on the surface, I for the most part, stay neutral and keep my emotions out of it. I do listen (to some big zingers a lot of times) and I act like it is all normal, interject a few hmmmmmmmmmmmmm's, oh my's and we're good to go.
Now, I'll also say that I only took two jail phone calls. It just rubbed me the wrong way to have those calls from A JAIL come to MY home on a personal level. Our difficult child didn't call us that much when she wasn't in jail. We didn't teach her criminal behavior, we fought tooth and nail to direct her to non criminal ways. So, I decided enough! I called the "Jail phone system" and told them to block our number. We would not accept anymore phone calls from jail. Our difficult child hasn't been back in jail that I am aware of and we haven't had to worry about those phone calls. Try it, you might like it!