Should I confront someone who is cruel?

My friend’s girlfriend is absurdly rude and cruel, nearly nonstop. It is to the point that the two of them are no longer invited to events or social gatherings. She is new to the area and our friend group, but we are all adults and have been nothing but kind and welcoming to her. We even made her a basket of treats when she first moved here. The examples are over the top, and nearly unbelievable. She yells, shouts, and states things that are shockingly cruel. When it happens it is shocking, and hard to believe so it becomes difficult to say anything. It is fairly obvious that she is experiencing some insecurities (and possibly some social deficits) and attacks as a defense mechanism. However, it is beyond anything I have ever seen in real life, it is worse than any bully in tv or movies.

Her behavior is abusive, and I am not sure how to move forward. I want to cut them out of my life, but I also want to confront her. I do not think confronting her will help anything, but I feel as if I need to stand up for myself. There is also the issue that I will be losing my friend by cutting her out. I am not sure what to do. I can provide examples, but did not want to waste time or spread her negativity and cruelty further. Thanks in advance for any thoughts, ideas, or stories that are similar. xx