How long are her walks and how many times a day? What other exercise does she get? Do you spend time training her daily?
Other things to try would be a food dispensing toy that you can put her dinner in, a game of hide and seek where you hide her food around the house or in various containers to get her mind working, non edible chew toys such as antlers or nylabones. Get her involved in a dog sport like agility or flyball.
Other things to try would be a food dispensing toy that you can put her dinner in, a game of hide and seek where you hide her food around the house or in various containers to get her mind working, non edible chew toys such as antlers or nylabones. Get her involved in a dog sport like agility or flyball.