No, if she had lacked free will, her Fiat would have been meaningless. She holds a unique place among humankind. As is the case with all of us, she being a human needed to the redemtive action of our Lord on the Cross, the difference in her case is that our Lord granted that redemtive grace at her conception, knowing that she would be His servant totally unified with His will.
So now that I have made an error today, I can go to sleep with confidence that the Angels will not come and take me up to heaven for being perfect. I just love it when I err and can stay here an extra day….