Should my wife feel bad?

Earlier this year, my wife and one of her good friends started drifting apart. Partially because her friend hated me, and my wife likes me, and because my wife had other priorities like devoting a lot of her time to flight school. Every few months my wife would check in on her friend and see how she's doing and always received the cold shoulder. 

This week, her now ex-friend dropped off a plate of cookies, but didn't say a word when she handed them to my wife. A little time later that day she texted my wife to tell her what an awful person she is and many other hateful things. My wife has felt horrible all week, so of course this move by her ex-friend put a damper on Christmas. 

My wife is beating herself up over this, but all I can see is major selfishness on the part of her ex-friend, especially her attempt to make my wife's Christmas a horrible experience. The fact she would wait till this week to bring it up and bring cookies before chewing her out seems to be one of the biggest jerk move she could have done. 

Should my wife feel bad?