My relationship with my mom was also strained, to say the least. She would not contact me but also would not hang up on me. When I went to Fl for my sisters wedding she actually told me that she felt that she had the right to talk to her own children. I was shocked and happy. After that I wrote her an 11 page letter and I told her that I was not trying to change her veiws but wanted her to understand why I felt the way I did. A lot had to do with the abuse I had endured and how the elders and the WTS responded. One of my sisters was there when she read it and she said that my mother said that I worte a lot of Apostate stuff. When my sister took it and read it (my sister has never been baptized) she pointed out that the only quotes that were there were directly from the WTS and the bible. My mom did not respond. After that I went to Brooklyn for the silent lambs March. My mom found out and was very upset. When I went to FL last she made it clear to me that she was dissapointed and she would not have any relationship with me. She did come to the beach on the last day I was there as we were having a family gathering, but she came just to see my kids. She did not even hug me goodbye. My sister said that after I left my mom broke down sobbing saying she should have hugged me.
I think my mom feels obligated to not speak to me because she has been taught that I am being wicked and she hopes that I will "come back to the truth" if she shuns me. I know this tears her apart but it tears me apart to think that she is so brainwashed to treat me in such a way. She knows of the abuse I suffered and she knows how badly I was treated and she KNOWS that I did nothing to be DFed over. All I did was went to the elders for help and answers. My "mistake" was not settling for "wait on Jehovah" , "have Faith" or "just pray more". But its the best "mistake" I have ever made. I just wish my mom could see that.
I guess you have to feel it out with your mom. If things are already strained you may want to take a lighter approach. Slip things in when she does not realize it. But be careful lest you lose her completely.