This is of course all theoretical....

If a physician was the first in their group to take a maternity leave policy and perceive something as being unfair, should that person strive to correct that? May be other than pulling the group leaders aside and mentioning that they should go over the policy with a lawyer (since it would be in her best interest to make sure the group is not liable for future law suits)? What if the unfairness does not affect her what so ever, but may affect future partners and employees?

I think you should fight for it, but if it's not in your contract or a policy is set, then I don't think you'd go very far with a lawyer. But that doesn't mean you can't fight to amend the policy!

What is your current policy?