Her unsatisfied "needs", her non- empathy, and narcissism makes her unbearable. We are the only siblings in the area and my husband is the youngest. Her presence fills most of our free time and discussions. We are both in counseling but she is the one who needs to address her issues. At 87 I know she never will. Even the people she eats with in the dining room are beginning to shun her. Setting boundaries sounds easy but let me tell you...I need help to cope.
If your mother-in-law truly has NPD, she will not change, even with psychiatric help.
Keep her at arm's length, if you can.
Vent about her to your psychiatrist as much as possible.
Also, does she have a golden child? Typically people with NPD have a golden child and they will often pamper and defer to this child and treat them more pleasantly than anyone else.
If there is a golden child sibling, get that sibling involved.
Have a "fine jar". Whoever starts to talk about her has to put a dollar in the jar.
Also have a session about guilt. In order to regain some of your life back, you've got to get over the guilt. There are lots of books on that subject too.
There is even a way to remember it "FOG" , Fear, Obligation and Guilt. Another good topic with the therapist.
Can you start by pulling away from her a bit?
(I'm assuming you and hubs are still working.) Can you visit one evening after work and one weekend morning or afternoon? Like JoAnn said, you don't need to be at her beck and call.
Refuse to talk about her at home unless it's an emergency. You are only reinforcing the "hold" she has on you.
Can you hire a part time caregiver to be with her part of the time (with her money, if possible)?
Did she used to belong to a church or club? You could call and have someone from either visit.
Again, maybe she needs more help now and you could transfer to Assisted Living.
You can say, "Gee, Mom, we're so sorry that we can't fulfill everything you need. But we'll look into seeing who can help you." You can acknowledge her needs but you can NOT give into every one of them. Practice roll-playing with hubby. It's difficult at first, but it gets easier the more you do it.