need birth certificate

My future daughter-in-law was adopted and she needs her birth certificate
for her driver's license etc. Her adoptive Mom gave her a birth certificate, grudgingly, and told her it would do her no good.
This has turned out to be true because it was a hospital certificate and when
she wrote to the state of Michigan to get an official copy she was told that her birth was never registered.
Does anyone have any suggestion?
Thanks for any help.