Okay so it is no secret that I LOVE GP. I've posted on her many times. And I especially love her GOOP newsletter. In her latest newsletter, there is a little note at the bottom to send her your questions and she will pick the best and respond in a future GOOP newsletter.
Email your questions to: email@example.com, put GOOP Questions in the subject line.
Also, check out Goop.com if you haven't already! Sign up for her newsletters, they're free! I've gotten some really great information from them! I especially love the fitness and cooking ones.