From what people say ..they do appear mates more than lovers
But when you've lost someone close to you, can can go a bit.. numb. I'm a cuddle monster but hated showing signs of affection when I lost close relatives. You can go a bit "in" on yourself so it might be that.
Also I don't think she's someone who plays up for the camera... maybe we just aren't used to seeing a "normal" relationship on screen!