Yes I am surprised that the vet hasn't fully explained everything to you, or run thorough tests including skull X-rays?? Or asked you to monitor her symptoms, and go back if all is not well?
There is another possibility -that this could be "Vestibular syndrome" which originates in the ear. But as it happened immediately following the fall, my thought is it could perhaps be damage to her head.
You need to take her back to a vet a.s.a.p.
If your own vet didn't examine her properly, then please do seek a second opinion from an entirely different vet as soon as possible!
I hope she will be okay.
What have you done to protect your dog from your children? It sounds to me like the dog may have suffered some brain damage from the falls... the vet has no idea? Did you tell your vet about the dog being dropped, how far, from what height, how did it land? On its legs or it head?