How do I beat the Siren without any magic or items?

I'm playing Final Fantasy V. Right after the giving my characters jobs, I went to the first village and couldn't really afford any magic - just Poisona for my white mage.

Now I'm in the ship graveyard area, and can't beat the Siren. And, apparently I can't go back to the village to buy any new magic spells.

As far as items go, I have barely anything - no potions, no Phoenix Downs, just a couple of Antidotes.

It seems like at this point my only recourse is to start over, because I can't seem to defeat the Siren. Any tips?

Solution 1:

The Siren's HP is 900, so if you think you can do that much damage to her than keep trying. If not then load a save from town.