Single friend causing marital problems

My wife and I have a new lease single friend. She got out of a 30 year relationship. for the last year, we have been allowing her to hang out at our house, invited her own family outings, and gone on vacation with her. Each time my wife and I are around her. My wife becomes very critical of me, becomes belligerent, calls me derogatory names. She does this in front of other people including our friend. If our friend speaks, I get yelled at if I ignore her, make any comments my wife feels is rude towards her. While our friend was in her relationship, my wife always took up for her against her significant other. Our friend planned a trip for her and her significant other, but the significant other got upset and refused to go, my wife stepped in and hook up for our friend. When our friend watched our house while we were on an extended vacation, she invited all my wife friends over for a brunch. She had never met any of these people in the past before. She drinks the same beer as my wife and states she enjoys the same hobbies as my wife. I’m becoming very suspicious of the two of them. I am currently in therapy working through all this. I feel that my wife and I may need to do marriage counseling. Since I have voiced my concerns to my wife, we have distance ourselves from this person.