
In my expereince you need to feed less than the actual amount for the dogs size.
When I fed my 17-18kg bitch AG prestige she got 150 - 175g.
You will probably find your girl fine on 75 - 100g.
If she eats 50g I would be happy. In fact I would give her just fifty for four days and if that is under what she needs it will pique her appetite.