Thanks for the extra information Karen, all helpful to know.
If you'd want to increase her weight it may be helpful to know that Protein contains 4 calories per gram, and Carbohydrates also 4 calories per gram whilst Fat is 9 calaries per gram.
So in a nutshell this means that for each gram of fat you feed her the calorie intake is more than double that of a gram of protein or carbohydrate.
Looking at the nutrients in "Evolution Naturally Adult" the amount of Protein is 38.9%, Carbohydrate is 31.1% and Fat is 16.7%.
You can see this information in the allaboutdogfood Dog Food Directory nutrient dials here :
You might note too when looking at the dials, the level of Protein is, as you say, above average; the level of Fat is average, and the Carbohydrate level is borderline average/above average.
If you wanted to consider perhaps a slight increase of Fat ( as a nutrient) with a slight reduction of Carbohydrate you can easily find foods in the dog food directory by moving the sliders (under the heading "Nutrient levels") to the values of the nutrients you want.
The link to do that is here :
I find these nutrient dials extremely helpful as they show in a diagram just what are the levels of nutrients in the foods we feed.
Sorry just wanted to add a little extra.....if you decide to tweak her diet, will you please try to change her slowly as she will be weakened by her illness at the moment, and the antibiotics may possibly be 'unsettling' her tummy too.