MIL is a cold fish and has always had a very strained relationship with DH (he has no happy memories of her growing up and remembers wishing he had a different mum from a very early age). She has very poor social skills and when we meet most conversation is initiated by me. She makes no effort with our dc as she claims she cannot hear them! She is also very religious but not in a good way - she is very critical and judgemental of others. MIL tries to put down and undermine DH also to the point where I have to tell her to stop being so nasty but she laughs it off, she will also roll her eyes at DH and shake her head at me expecting me to join in. There is a SIL as well who believes she has had a great upbringing, and when we talk she has a completely opposite opinion of MIL. SIL manipulates situations to make it look like she is good and DH is bad. We have caught her out on a few occasions, but think it happens a lot. She has also relayed untrue information about me to MIL to make me look stuck up. SIL is very competitive with DH and is, I think, struggling with the fact that DH is doing very well in his career, and our dc are also currently doing very well - we appear to have a very good life at the moment, but work hard for it. FIL unfortunately passed away before I met DH.
As far as we know there has been no incident, but for the past few years communication between MIL and DH has dwindled from a weekly phone call from her or DH, to a phone call every 3-4 weeks always from DH. She never phones. She never visits (we have been there past few times.) It has now got to a situation where DH is refusing to phone MIL as is waiting to see if she phones him. I am now starting to feel guilty - should I have made more of an effort to smooth along their relationship? Should I interfere and phone her? The situation makes me feel so uncomfortable.