Princess Alexa is the deuteragonist in the 2008 animated film, Barbie & the Diamond Castle.
She is played by Teresa and voiced by Cassidy Ladden.
Alexa is a gardener that was lives in the woods with her best friend, Princess Liana. They are mostly share their love of music and sometimes they sing together along with their guitars. One day, a storm ruined their beautiful garden that they sell to make money.
One day, they are meet an old woman, with a sack full of rusty things, when they were going to town to sell the flowers left from the ruined garden. When Liana has shares her lunch with the woman, she is offered a gift from the woman. Liana is hesitant but Alexa tells her she will hurt the woman's feelings if she doesn't. Liana chose a rusty mirror.
Alexa and Liana got back into their house and Liana washed the mirror, and it turned out to be a beautiful mirror with sparkly flowers with gold, swirling stems. While they're both singing while they're clearing up the whole mess, both of them heard that someone is also there with them. It turns out that there was a woman inside the mirror.
Her name is Melody, and the trio embark on their journey to a hidden Diamond Castle, where she study as an apprentice. Along the way, Liana and Alexa found two little puppies on their way to the Diamond Castle. Alexa named hers Lily.
- Her name was originally Isabel.