You are right, in this game there is no option to show favoritism for any girl, the concept is family, but your decisions do unlock different scenes and directly influence the way the ending is approached depending on the character of your answers, but still it is like in real life, there are people who sometimes have more power over oneself and independent of what you decide or say, they know how to twist the situation in their favor and in this game there is that power... a little lady somewhat scheming. Greetings