If I'm not misremembering: Single one out and stay with that one til you kill her. If you have the Medusa Head yourself, I think you can use it on them to freeze them then break them like they do you. I can't remember the strongest combo for you here. Box, box, triangle, I think?
Don't get frozen in mid-air though, I bet you already know that.
Wiggle your stick (no, not that one) to get free if the Medusas freeze you.