After Kayla finds the first Blue-Eyes White Dragon, she uses Starter Deck: Kaiba, with some modifications and continues to use this deck even after finding the second Blue-Eyes White Dragon. This deck is only partially seen once, during her duel with William, when she reveals the Blue-Eyes White Dragon to the world. Once Pegasus gives her the final Blue-Eyes White Dragon, she begins to use a real deck, as seen below.
First Deck
Monsters: 21
1x Baby Dragon
3x Blue-Eyes White Dragon
1x Cave Dragon
1x Curse of Dragon
1x Dragon Piper
1x Emerald Dragon
1x Gaia the Fierce Knight
1x Hoshiningen
1x Koumori Dragon
1x Lord of D.
3x Paladin of White Dragon
1x Sapphire Dragon
1x Spear Dragon
1x Time Wizard
3x Troop Dragon
1x Winged Dragon, Guardian of the Fortress #1
Spells: 15
1x A Wingbeat of Giant Dragon
1x Cost Down
3x Dragon Treasure
1x Luminous Spark
1x Monster Reborn
2x Polymerization
1x Stamping Destruction
1x Swords of Revealing Light
1x The Flute of Summoning Dragon
3x White Dragon Ritual
Traps: 4
1x Burst Breath
1x Dragon's Rage
1x Ray of Hope
1x The Dragon's Bead
Extra Deck: 2
1x Gaia the Dragon Champion
1x Thousand Dragon
Second Deck
Monsters: 25
1x Armed Dragon LV3
1x Armed Dragon LV5
1x Armed Dragon LV7
1x Baby Dragon
3x Blue-Eyes White Dragon
1x Cave Dragon
1x Curse of Dragon
1x Dragon Piper
1x Gaia the Fierce Knight
1x Horus the Black Flame Dragon LV4
1x Horus the Black Flame Dragon LV6
1x Horus the Black Flame Dragon LV8
1x Kaiser Seahorse Dragon
1x Lord of D.
3x Manju of the Ten Thousand Hands
3x Paladin of White Dragon
1x Sapphire Dragon
1x Spear Dragon
1x Time Wizard
Spells: 11
1x A Wingbeat of Giant Dragon
1x Burst Stream of Destruction
1x Luminous Spark
1x Monster Reborn
2x Polymerization
1x Swords of Revealing Light
1x The Flute of Summoning Dragon
3x White Dragon Ritual
Traps: 4
1x Burst Breath
1x Dragon's Rage
1x Ray of Hope
1x The Dragon's Bead
Extra Deck: 2
1x Gaia the Dragon Champion
1x Thousand Dragon