Randi, I feel for you. I cringe when I think of what it will be like as Kai'a gets older. At 14 weeks she is already a ball of pure energy and although she is normally pretty good and clams well when we ask her ... the energy is always right there at the surface, ready to bubble over.
I, like you, work a long week and have to use my time very wisely in regards to exercising Kai'a ... we are up extra early to have a 45 - 60 minute walk before work, a rotating shift of playmates while we all get ready for work/school/collage after breakfast, then home at lunch for at least an hour of play, Kai’a then has Devyn and Steve all afternoon, we have another long walk after dinner, (still to young for the park) then play time at home or in the yard until 9 or 9:30. It seems like if we are awake, she is in hyper-drive. And even though we all love our dogs, sometimes we just need a minute (or several) to ourselves, to share time with our families and to just relax. I sympathize.
My advice to you is from my Angel Dogs ... They will never, ever, physically tire. You need to mentally tire them, (which several people have mentioned already). Mental exhaustions is achievable. The chewing & mental games are all really good, but one of the things that I found really worked was basic training mixed individual tricks.
Instead of playing ball for 2 hours at the end of the night, I would maybe play ball for 30 minutes and then spend the other 30 minutes to an hour working on a trick with the ball or on variations of basic commands that could be made into a new game/trick with the ball/squeaker/rope/yourself etc. I would do all kinds of neat tricks and "plays" as Devyn called them with our other dogs. Eventually I would use time that I would usually try to be running them silly, just working on these mental exercises and what I found was that I ended up with more "dog free" time each day ... and they slept well through the night.
Kai'a is already a good sleeper. With a few exceptions (like a night she was up running around until 1:30 am!!!

) she settles and goes down at 10 or 10:30. We don't get up to take her out at night anymore and weather she is in her crate or on the sofa by us, she will start to chill out, by herself, around 9:30. I just try to set aside time from 7:30 - 9 to work on these mental games and training. I get Muppet (Devyn) and Steve to join in and it's a family thing.
Bailey is also a teenager ... you say it yourself, it's just a bratty time for them. I think she will come out on the other end of this phase to be a perfect little sheltie. One thing that is said about this breed is that they will adapt to the lifestyles of their owners. She will blend in to whatever schedule you set for her and in the end, she will be like an extension of your right arm; there and moving freely, without thought or correction. (Man I think the NightQuil is getting to me ... sorry if this is all fuzzy,

I should know better to respond while under the influence of drugstore flu pharmaceuticals

)
You are a fabulous FurMom. You care so much for Bailey and your other pups. You want nothing but the best for them. Bailey will get there with your guidance and direction and your dedication to her. I look at all of our dogs and all I think about is how do other people who just “own” their dogs do it? We invest so much of ourselves in our pups; our time, love, money, our hearts. In the end, it all comes back to us.
Don't worry dear ... you will sleep again one day soon. Promise