Mirta/Series

Pre-Series
As a child Mirta was bullied in school. But then she meet Lucy who became her childhood best friend. Later in life her and Lucy would go to Cloud Tower to become full fledged witches. According to Lucy, Mirta was very shy during the entrance exam and Griffin barely let her in. But Mirta still got accepted into Cloud Tower.

Season 1
Mirta first appeared in "Friends in Need," saying that witches and fairies should be friends because fairies are not that bad, but everyone thought that it was a ridiculous idea and laughed (especially the Trix). Darcy told her to just be quiet and sent a dark bubble at her that covered Mirta's face and suffocated her for a bit before releasing her.

Later in "Betrayed!," an onset started when all the witches were the Trix's reinforcements (after Musa hit Icy and the latter fled) but Mirta was the only witch who did not fight against the Winx, reasoning that ganging up on someone is pointless.

In "Miss Magix,", Mirta tries to stop Lucy from going to the Miss Magix contest because she knew the Trix will be "helping" her and if the Trix were part of it that would mean trouble, but Lucy ignores her plea and decides to go anyway. During the pageant, Lucy was humiliated by the Trix.

In "Bloom's Dark Secret,", Mirta is being tested by Griffin and hesitantly answers Griffin's questions. As Griffin writes down Mirta's results, she walks back to her seat only to see the witches mocking Lucy for her humiliating contest results. Despite all the Trix had done to her and Mirta's reasoning, Lucy still wanted to be part of the Trix and dismissed their friendship. Out of concern for Lucy and anger toward the Trix, Mirta decided to act and foil the Trix's next plan.

On the windswept terrace, Mirta uses her powers to find out that this time the Trix had managed to completely fool Bloom into believing that she is a "witch" and with Bloom vulnerable they decide to take advantage of this and steal her powers. Mirta goes to the forest to look for Bloom (despite never meeting her in person prior) and explains the Trix's plan to Bloom. For interfering with the Trix's business, she is punished by being transformed into a pumpkin. Flora keeps the pumpkin in her room and takes care of it, trying several times to turn it back to normal. By the end of the first season, she is turned back into a girl by Flora and transfers to Alfea.

Season 2
In "Party Crasher," she is seen with Ahisa and Kimmy at the entrance of Red Fountain before it's grand reopening. She greeted Lucy as she walked up to the entrance, but Lucy ignored her.

In "The Show Must Go On!," she is part of Aisha's at Musa's concert. In "Twinning with the Witches," she is the Winx's guide while they are transfer students at Cloud Tower. While at Cloud Tower, Mirta visits Lucy and they share memories of their childhood. Lucy accepts Mirta's desire to be a fairy and Mirta does the same for Lucy's wish to become a full-fledged witch. She tells Mirta that not all witches are like the Trix and that there are proud and strong witches like Miss Griffin (implying Miss Griffin is now Lucy's role model and that she no longer wants to be like the Trix). Mirta later finds herself caught up in yet another battle with the Trix.

In "The Phoenix Revealed", she is seen dancing with Lucy and taking pictures with the Winx Club.

Season 3
In "The Princess' Ball,", she was mentioned when Tecna said she had sent Mirta an invitation to Stella's Princess Ball and that she had accepted it.

In "Alfea Under Seige," she is seen fighting the witches alongside other Alfea fairies.

In "A Trap for Faires," she is seen accompanying the Winx to Cloud Tower to search for answers about the disappearance of Faragonda after her battle with Valtor. She especially wanted to search for Lucy and find out why the witches attacked Alfea. Aware of their presence, Valtor creates an illusion of Lucy and Mirta falls for it and is trapped in the dungeons

Season 5
In "Return to Alfea", she is seen during Faragonda's speech and the arrival of the Winx.

In "Trix Tricks", she watches the Annual Wind Rider competition.

In "The Sharks Eye", Mirta makes a cameo near the end of the episode watching Musa and Riven preform.

The Secret of the Lost Kingdom
She and her classmates are seen during the Day of the Gift ceremony. When Mandragora attacks Alfea, she starts taking down one of her monsters bravely with fairy powers and after with witch powers but Professor Wizgiz finishes it more comically. Later, she appears with the teachers, pixies, and fairies to restore Alfea after the battle.

Magical Adventure
Mirta takes part in the rivalry of friendship between Fairies and Witches. The Witches of Cloud Tower pull a prank on the Alfea Fairies by putting a spell on the food; it turns whoever eats into a frog. However, Mirta manages to the throw cake at Lucy before the latter could, thus turning Lucy into an amphibian. Mirta then frightens the Lucy-frog away, giggling at it. As it is relatively easy for Lucy to be turned back, it is all in good fun and so the prank backfired a bit on the Witches.

Revenge of the Trix
Mirta interferes in the Trix's plan to steal Bloom's Dragon Flame by warning Bloom. Later on, during the fight against the Trix, Mirta is turned into a pumpkin by Icy and is subsequently taken to Alfea to be cared for by Flora.

The Battle for Magix
She is back to normal at the party after the Trix are defeated by Bloom.