I don't get the lopsided arrangement.

My mother was forbidden to see my brothers 4 sons. We're not sure why to this day. What we think happened was she got angry at my mom for putting one of the boys in a high chair - which she called torture devices. Mom passed away without really knowing those grandchildren. Which was a shame - despite being a terrible mom to me she was outstanding to my own children.

My own relationship with my SIL was odd at best. One moment we would be best friends, others I would be basically a free babysitter, and others she wouldn't talk to me. In all honesty we thing she is bipolar or berderline. (she and my brother have not been together since the 4th was born)