Myster Solved!!!! I finally found the singer of the Kaiser Permanente "Thrive - Find Your Own Thing" commercial! It was a huge mystery and nobody knew the answer.
I tracked down the ad agency that made the commercial and here is their reply:
"Thank you so much for your interest in our music. In response to your request, unfortunately our productions are works for hire, and we are not at liberty to release them independently.The singer is Heather Ogilvy: http://www.heatherogilvy.com/ Best wishes --- Human "
To see the commercial on her web site and "prove" she did it, follow this specific link to her site:
Here's the original commercial on You Tube;