I agree with Reg on the raw food calculations.
How much does Libby currently weigh?
Has she had a fecal exam or been dewormed?
The amount to feed is somewhat subjective, if she's still hungry and not gaining weight personally I would increase the food per serving in small increments. The volume can always be adjusted up or down once she gets to an ideal body weight for her age, activity level and current weight.
Several pictures are in order