Princess Johanna was Peter III's aunt and preferred him over Sophie (Catherine II). I think Sophie had at least one younger brother as well and Johanna payed more attention to him and Peter than she did her own daughter. Personally, I think she wanted Sophie to marry her Russian cousin just to get rid of her. Like Grand Duchess Anastasia, her mother in particular was disappointed that she was not a boy, but unlike the grand duchess, Princess Sophie was unloved by her mother. Her father I'm not so sure about.... he seemed to be away on trips an awful lot, but I could be wrong on that assumption.