Insurance?

So, we got a rather large (lets just say thousands of dollars) bill in the mail from the hospital for Sophie---and we just figured it was an oversight?  Apparently the insurance didn't even know she existed, so the lady entered her in the system and said to have the hospital resend the bill.  Then, in her random mumblings, she kept referring to one day and did she live one day and blahblahblabh.  

Does anyone reading this know anything about that?  Does a baby have to live a certain amount of time to be covered by insurance?  That seems cruel and insane!!!