i would think about your dog's temperment. any of the "water" dogs would be a good companion as long as the dog has the same energy level. i have had issued with female dogs not getting along with other female dogs. (worst dog fight i ever saw was between two females who were trying to kill each other) another lab or maybe a golden would be a good mix. but only if your current dog wants to share her family with another dog. try her out at a dog park to see how she responds when you fuss over another dog.