I think I would get to the bottom of why she has a need to be in the same room and see if there is another way she can get her needs met and move her out of your room. Why can you not all have your own rooms and schedule time each week in different dynamics... two of you, then the other two, all of you... even in bed for a short time and then everyone out for the rest of the night... all this would take trying and negotiating until a balance is reached.
I agree with the spontaneity thing. You have been fortunate enough to be able to enjoy that at all! Roommate, kids... all equal no spontaneity. Maybe you need to negotiate an empty house with only you and your love at home sometimes.
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