how does double coverage health insurance work?

If my partner is covered by my health insurance as well as her own, how do the bills get paid? I am assuming the bill first goes to her insurance and then to mine?

How can I get health insurance coverage from Humana when travel in China?

I am self-employed and cannot get health insurance do to my weight? How can I get good coverage?

http://abdurrahmanwahid.cn/health-insurance.html