@Pen- MIL lives 9 plus hours away, so going to any sessions with us was not possible. However, DH and I used to talk to MIL all the time regarding DD. MIL was informed about everything going on with DD up until we had our last argument. When we would talk to MIL about the SPD and CP she would say "Wow, they have an excuse for every parent out there now." She thought I was making excuses for my "laziness". Upon visiting, instead of focusing on the positive, she felt it better to tear me down and tell me what I was doing "wrong" to hinder DD's development. I tried explaining that it was all part of the sensory and CP disorder and that things would just take a little longer for her. She didn't like to hear about it and she didn't understand that pushing DD to do things that she was not ready for was a very bad thing to do. MIL wanted us to do things her way when it came to parenting and she could just not understand that that would not work for DD.
Now, the "personal business" that MIL felt the need to intrude upon were, indeed, very PERSONAL. Like our sex lives, method of birth control, our preference in churches (she wants us to go to a Baptist church only. We are nondenominational Christian.), our choice to home school DD (that was actually recommended by DD's PCP. She told me the DD would be illiterate if I taught her. DD reads 2 grade levels above her peers). Even worse, she would get involved in our relationship spats. My DH would tell MIL about some of our arguments and instead of just counseling her son and giving him some encouragement or good advice, she would feel the need to call me and yell at me. I don't think that MIL should have a part in our arguments, even if she knows what is going on. My DH is very capable for speaking for himself. I think he would just call her talk and to think things out, but she always had to get in between us. To make matters worse, she would even "twist" the things that he said to get me fired up and then another argument would ensue because of her embellishments. Eventually, I figured it out and ignored it, but I can't help but feel that she liked to cause drama between me and her son. So please, don't assume I meant the MIL was in the dark about it all. She was way too into our business. Really :/
I want MIL to have a relationship with us, but she is going to have to be respectful of our choices and come to the realization that my DD is a special needs child. She has had her opportunity to raise her children as she saw fit and now it's our turn to do the same. Every child is different and what may have worked for her does not mean that method will work for our children.