Where is she getting her carbs, vitamins, fibre, and minerals from?

If she isn't touching the complete food which has all of the above in and then some, I would suggest mixing in a bit fo the mince food with a bit of the complete food to two or three meals a day. Hold some back if you want to use it as tit-bits but once she has eaten remove the bowl.

If we give access to food all day whenever they want there is no incentive to work, there is no need for them to even bother doing anything as they have the means to survival right there when they want it. If you put the mixed food in a bowl, make her sit and wait, let her eat and then as soon as she walks away from the bowl remove the food then you are controlling the resource, she is getting a lot of nutrients and energy inside her that she can use for a longer period of time rather than just getting the odd bit for doing this and that but the energy amount she will get from tit-bits will not be enough to keep her concentration levels up.

If you were training a kid would you feed sweets, crisps and chips every so often and leave a plate of nutritious veg and pasta ont he side in case they want some? No. You'd make them eat full meals to keep their stoves burning which allows them to get the energy they need to learn. Sweets, crisps and chips are high value food items to a child which is why they are given as a treat. Raw meat and bones are high value food items to a dog which of course they are going to choose over the complete dry food everytime. Mixed in with the dry complete food creates a full all rounded meal.

If a carnivorous animal makes a kill or needs nutrients other than that which can be found in meat they will eat the stomach contents of the kill or they will eat grass. Dogs are fairing ont he verge of omnivore so they need and can handle vegetation based nutrients, vitamins and minerals to fuel their bodies.

Try mixing in the raw and complete to make two to three small meals for a week and see if or how fast you notice the difference in your dog's attention span, energy levels and willingness to learn.