I need advice on how to respond:?

Well, I'm not a completely religious person, but I do believe in forgiveness. However, I also believe in knowing I've got a good thing when I see it. You're just asking for trouble if you call her. I understand that it's terrible knowing someone is angry with you for, apparently, no good reason. It was rude to not even ask to stay with you, and it was even worse of her to take the briefcase. I'm slightly superstitious, and I feel like it was a terrible thing to do, to take that briefcase before your stepmother had ped away (I'm sorry for your loss, by the way). You have already shown mounds of patience by dealing with her antics for the past 10 years. If she's angry, let her be angry. You did nothing wrong, so don't fret over it. When she's ready to talk to you like a rational person, she will. Or she'll figure she needs to drop by unexpectedly, again, and you'll have to deal with her. If that happens, don't take this behavior. It's your home and life she's disrupting, and if she's ungrateful and critical of what you have, then she should just go home. Good luck!