After a prank-gone-wrong, Marisol betrays Fiona, sparking a rivalry. During the season 11 finale, it is shown that Marisol and Fiona have somewhat made amends and are on good terms with each other. In season 12, it is revealed that they have become friends through working together on student council.
In Underneath It All, Fiona meets Marisol in science class trying to escape from Imogen. Marisol pretends that she has saved Fiona a seat. The two girls then introduce themselves to each other. Katie then walks in and introduces herself. Fiona, wanting to impress them as well as gain their friendship which would lead to popularity, asks them if she should throw a party; Marisol enthusiastically agrees. Throughout the episode the three discuss who should be invited; Fiona reveals that she invited Imogen, much to Katie and Marisol's dismay. During the party, the party-goers play truth or dare. Owen dares Fiona to drink an entire bottle of alcohol. Imogen, aware of Fiona's past as an alcoholic, jumps to her defense by bluntly stating, "Fiona can't drink that because she's an alcoholic."
Marisol then harshly says to Imogen to not joke about something as serious as alcoholism. Fiona, wanting to change the subject, says that she does not want to vomit at her own party; she suggest that instead to play a senior prank. The prank was that all party-goers will wrap tin-foil around every object in the Degrassi Cafeteria. While the prank is being committed, Imogen decides to explore the school. Marisol follows after Imogen to keep an eye on her. While Imogen is in the theater, listening to her mp3 player, the doors are locked. Marisol, having lost Imogen, wanders back to the cafeteria when the group hears other people -presumably the janitors- coming. They all escape, aside from Imogen who is trapped in the theater until she is found by the janitors and suspended for the prank.
Marisol convinces Fiona to persuade Imogen to take all of the blame. Fiona goes over to Imogen's house and convinces her to take all of the blame, she then reports back to Marisol and Katie. Marisol then admits to Fiona and Katie saying that she was the one that locked Imogen in the theatre to avenge the fact that she called Fiona an alcoholic. Fiona, feeling remorseful of what happened to Imogen, decides to persuade Marisol and Katie to confess with her to Mr. Simpson. Marisol agrees and says that because it is important to Fiona, it is important to her and Katie. Later, Marisol and Katie are in principal Simpsons office with Fiona, ready to confess. Fiona confesses and Katie and Marisol allow her to take all of the blame. Fiona tries to explain that both Katie and Marisol were there as well, but they deny it.
In Can't Tell Me Nothing (1), Marisol steals Fiona's idea about the 'coffee house' proposal. At first, however, Marisol denies the idea seeing as how it came from Fiona.
In Can't Tell Me Nothing (2), Fiona confronts Marisol for stealing her idea.
In In the Cold, Cold Night (1), Fiona excitedly reports to Imogen about Katie's rumored prescription pill addiction, which has landed her in rehab. They head into an active student council meeting that is being held by Marisol. Marisol than ask Mo to escort both of them out. Later, Fiona goes to Mr. Simpson and presents him with the idea of a safe, daytime, Degrassi only carnival. Mr. Simpson tells Fiona that she must work with Marisol to make the carnival happen. Fiona propose the carnival idea, however Marisol says its too much money and would bankrupt student council's budget. Fiona then says she will pay for it herself, which causes Marisol to ask her if she has ever been required to work for anything in her entire life.
In In the Cold, Cold Night (2), Fiona is seen giving Marisol the money to pay the carnival workers as well as a bonus for the last minute set-up. Marisol then says she should have trusted Fiona to come through with money. Fiona then informs her of her current situation with money. This disappoints Marisol because she states that she realized how Fiona could be useful during the next semester by supplying money. Marisol then asks where her sidekick (Imogen) is, Fiona glumly tells her that they are no longer not speaking. Marisol jokingly says that they are drama before she runs off to pay the carnies and make sure her boyfriend, Mo, does not eat another candy-apple.
In Got Your Money (1), Fiona returns to school, and her and Marisol appear to be on better terms. Marisol informs Fiona that Katie is no longer the school president, and Fiona and Marisol are now running the entire student council. Marisol tells Fiona that for their next event, they have to include the Toronto Ice Hounds in on the decision planning to make up for assembly. Fiona admits that she had high expectations for the semester, but it has been a let down, and Marisol asks how her and Imogen are doing. Fiona says that Imogen doesn't want to spend time with her because she joined a band, though Marisol tells her that it's good the two have different interests and that Fiona is being too clingy. The two plan to have a dance, so that Imogen and Mo's band could have their first gig.
In Got Your Money (2), They introduce Whisperhug at the dance.
In Degrassi: Las Vegas, they both go to Vegas not knowing ithat the one one is going. They also both play instruments in the background when Drew sings to Bianca.
In Bitter Sweet Symphony (1), they are both handing out colored scarfs for Spirit Week.
In The Time of My Life, Marisol calls Fiona to let her know the seniors are about to do the cap toss.
- Fiona had a conflict with Marisol's best friend Katie while Marisol has a conflict with Fiona's ex-girlfriend Imogen.
- They were both members of the Degrassi Student Council.
- Marisol also had conflicts with Drew and Bianca who are both friends with Fiona.
- Fiona is first person that Marisol is not in a conflict with that Katie has a problem with.
- Marisol referred to both Fiona and her ex-girlfriend Imogen as drama.
- They both kicked each other out of the Student Council room.
- Feud ended when they planned the Winter Carnival together.
- Marisol used to have a crush on Drew, who was Fiona's roommate.
- Fiona planned Drew and Bianca's wedding. Marisol is enemies with these two people.
- Marisol always tells Fiona that she is clingy.
- Marisol has accused Fiona of using her money to make friends.
- Marisol had a dislike towards Eli, who is friends with Fiona.
- They both love to plan and attend parties.
- Both were in a relationship with a member of the band WhisperHug.
- Both were present at Drew and Bianca's almost wedding in Vegas.
- Drew was attracted to both girls at a point in time.
- Both have had a conflict with Drew.
- Marisol is still in a conflict with him.
- They both made their final appearances in The Time of My Life.
- First Friendship:
- Second Friendship:
- Start Up: In the Cold, Cold Night (2) (1145)