I've heard a lot of ages of how old the Winx are and here's my opinion . . .

Season 1

Winx:

Bloom - I think she's like 15 in season one because she's a freshman.

Stella - I know the Stellais older than the other girls because she failled her first year at Alfea so I would say she's 16

Tecna - I'm pretty sure that she's 15 like Bloom.

Musa - I think Musa's about 15.

Flora - Flora's is about 15 too because she's a freshman at Alfea.

*NOTE LAYLA HAS NOT JOINED THE WINX YET SO I DIDN"T PUT HER ON*

Specialist:

Sky - Is about 16 because he was there last year *As said by Stella*

Brandon - Is also 16 because...

Italian
Enchantix
Oh, Enchantix
Polvere magica
Potere al massimo Enchantix, piu forza mi dara
Potenza massima
Polvere
Mi Fata
Potere Enchantix
Ali di Luce, Super Poteri Winx!
Enchantix

English
Enchantix
Oh, Enchantix
Magical powder
Maximum power
Enchantix, powers upon me
Powerful magical,
Wonderful,
Dimension.
Powerful, Enchantix.
Incredible vision,
Incredible power, Winx.
Enchantix!

Hungarian
Átváltozás
Fesd föl az égre,
Itt vagyunk végre.
Átváltozás!
Repülj a fénybe.
Ha mégsem szeretnéd,
Fagyaszt a, rideg tél.
Varázs átváltozás,
A hihetetlen csodaerő a kincs.
Így hát Winx!

Hebrew
Enchanti-x! Enchantix
אבקת...

Witch

Ice Prison
Frostbite: Icy exhales an icy wind at her opponent.
Iceberg: Completely freezes a surface of area.
Crystal Cage: Traps enemy in an ice container.
Arctic Blast: Releases a fragment of ice energy, focusing it, which then explodes, leaving the enemy unconscious.
Ice Coffin
Ice Crusher: A huge chunk of ice builds up next to an object and grows until the thin piece of ice holding it up breaks, causing the chunk of ice to fall on the object and crush it.
Blizzard: Creates a blizzard.
Ice Attack: Shoots a disk of crystals.
Ice Hail: Attack that wipes out everything in her path.
Ice...