As for attacking the queen, you first want to attack her arms and get rid of them. Then her crown should fall off and you can go for the head (stick to jumping instead of the hammers for this). There's lots of dodging in this battle, too, so stay on your toes.
Keep these in mind too:
+you could be underleveled and need to level up by beating on some monsters.
+Keep your equipment/badges up-to-date by visiting shops.
+Remember, for boss battles, you can never have enough items or use enough special attacks (aka the Bros. Attacks)
+memorize the boss's sequence of attacks, so you know what's coming
Hope this helps; good luck. Don't end up like this -->:tombstone