Answer:
In a blender/food processor, add:
I pack low fat cream cheese (like Philadelphia light)
half its volume in water (bit by bit until you get the consistency you want)
fruit puree (if liked)
2-3 teaspoons caster sugar
Blend it. Chill. This is a basic recipe, which works when it is light and airy from the blender/processor. Flavour it any way you like.