If you're looking for gentle but fun tricks to re-engage the dynamic, something that's subtle but possessive and feels very nice is to hold her wrist instead of her hand. If you're sitting or lying together, or even on a walk just grab her wrist. If you want it even more subtle (walking somewhere crowded) then move your hand lower so that you are wrapping her hand in yours, so that you are still containing her but it looks more like hand holding to passers by.