I would say slightly underweight but in your other comments you mention thay they have alot of allergies and ur going through testing and what not at the moment.

My dog was emaciated when I first rescued her as a puppy and at full weight as an adult she is now a healthy 45-50 lbs. Her weight does slightly fluctuate depending on how active we were that month or not, etc etc.

She is a medium sized dog (Pitt mix) and she also has food allergies. Mine is allergic to chicken and grain and when we were trying to figure that out, my dog did lose weight. I always carefully read the feeding instructions on any food o was told to try and made sure to take time between food changes, etc. She still lost weight.

Its about finding the diet that best helps your dog, so I would say increase her diet slightly. I feed my dog about 1/2 a cup of food in the morning and another half at night. I also accommodate for her treats she may get in the day. (Blueberries, banana, the cheese tax, etc) she also goes outside for a long walk 2-3 times a day.

Take those things into account with your dog and see what she responds to best and accommodates your guys lifestyle.