Mom usually has more serious impact on a child than any other adult, and the mother is not only a source of great love, but also a source of rules, prohibitions, restrictions and so on. A typical situation: the child has fun with grandparents, then there is a mother and begins — why did not eat soup? Take away the wreckage.
Don’t go grandpa on my knees they hurt. Come on we gotta get up early tomorrow. And so on. And even worse if she sat with grandpa and grandma in the kitchen, got hold of all these spoiled. The whims, tantrums, disobedience is even a caricature, but it is a natural reaction to the interruption or restriction of any pleasant for the child processes and events, upholding its right to freedom and attention.