As a DIL I think that in the end MILs - and mothers for that matter - get back what they give out. I started married life trying to treat both my mother and my MIL equally, desperately trying not to spend more time with one set of parents than the other. Over the years, my mother has stepped back and hasn't interfered once, whereas my MIL has not only interfered but has constantly undermined me and chosen to favour the grandchildren who are more like my husband's side of the family than mine. She is no doubt feeling hard done by that we don't see her very often these days, but she has only herself to blame.