How can I remove mildew stains from a crocheted dress?

I want my daughter to wear the hand crocheted christening gown that my Grandmother made for me to wear when I was a baby. I had my father go pull it out of storage from his house, and I was very upset to find that the dress had several spots of mildew growing on it! It has alot of very sentimental value to me, being as that my Grandmother made it and she's since ped. I would very much like to put my little girl in it in April for her Christening, but I have no idea how to go about getting the stains out. I'd love any suggestions! Its a white crocheted gown, matching bonnet and booties. Thank you!!