That's a pretty broad generalization. Most historians agree that Maria P. loved her brother Dmitri more than anyone else throughout her life. Her relationship with her son Lennart was a bit different, as they did not become close until later in her life. As a royal, MP was raised to behave properly so she was probably what we would consider "nice" to a good many people. For example, she looked after her parents in law, the Putiatins, for many years after her divorce from their son, something she was not obliged to do.