Okay, this is going to be long but I have been trying to think this through and wanted other opinions. My MIL is very controlling so much so that she has pushed and pushed until the only family she has left is us. These are examples of her behaviour.
Every night my DH has to ring her between 11pm and midnight, if he rings earlier she ignores the phone until he rings at his "allotted time" my words not hers. If he doesn't ring her she will us in a panic. If we have gone to bed and turned the phone off she will ring our neighbour, my Mum, my brother, DH's friends,etc,etc in a complete panic as she assumes we must be dead. If she gets no response from ringing she has been known to catch a taxi to our house and hammer on the door in the early hours of the morning until we let her in.
Since my DH was made redundant 2 years ago MIL now also rings at least 5 times during the day. It's got to the stage where we are missing lots of important calls because we have started ignoring the phone. I cleared out this weeks phone messages tonight and there were 37 messages from her in a week 
. The last message said in a really pitifully voice DHname "don't forget about me....... I'm still here". Argh, as if we could.
MIL comes to our house twice a week so it's not like we ignore her. It's really getting me down and is effecting our marriage as I am so sick of it.
MIL also has a picture of Jesus she keeps in her purse which was apparently blessed by a holly man and sprinkled with sacred water. she takes this picture out all the time and brushes it against us. I shouted at her to stop it last time I caught her doing it but she still does it. DH has spoken to her about this and she said she is blessing us to keep us all safe.
MIL has always been a bit strange for instance when she uses a bus she has to change her clothes when she gets home because she thinks she is going to catch something. She turns the smallest problems in her life or our life into a complete wailing drama, honestly I could write a book. My DH has an OCD and I think it comes from his mother.
We can't go no contact as she is 84 and literally has no one else but this is driving me mad and has now got to the stage where I don't even want to look at her anymore never mind have a conversation.