|Intimacy Level||Enemies, former friends|
|Conflict Started||Underneath It All|
|Conflict Status||Good Terms|
Season 11In Don't Panic (2), Fiona is seen debating whether to vote for Katie, Mo or Marisol, calling Katie a liar.
In Underneath It All, Fiona sets her sights on being friends with Katie and Marisol. In class, Katie introduces herself to Fiona, and Fiona invites her and Marisol to a party she throws, which they agree to go to. When the three are walking in the halls saying that the guest list must be exclusive, Fiona suggests Imogen to come, they don't like the idea, but then think it's not so bad after all. At the party, when Katie offers Fiona a chair in the social committee, Imogen comes out in a pretty black dress. Fiona thinks she looks gorgeous, but Katie gets jealous when her boyfriend Drew agrees with Fiona. When playing Truth or Dare and Fiona is dared to chug tequila, Imogen blurts out that Fiona's an alcoholic, and Katie questions this, but Fiona denies it. At Degrassi, Katie has her key to let in all the seniors for a prank by covering the school in tin foil. When Imogen and Marisol go down the halls of Degrassi, Marisol returns without Imogen, Katie tells Fiona and Marisol to just come to avoid trouble. The next day, Katie and Marisol convince Fiona to tell Imogen to cover keep quiet about the prank. When she returns to tell them, Fiona says they should just come clean, but Katie denies this. Fiona, upset for treating Imogen badly, tells Marisol and Katie that she actually is an alcoholic but is recovering. When Fiona tells them, Imogen got suspended. Fiona once again says they should come clean. to which Katie worries about, and Katie somehow agrees since Marisol forces her. In Principal Simpson's office, Fiona begins to tell the truth, but Marisol and Katie cover it up with a lie to get Fiona in trouble. Later, Fiona yells at Katie but Katie tries apologizing and hopes they are still friends and offers her a chair in the social committee, which makes Fiona angrier and blurt out they were never friends and friends don't get other friends in trouble. Fiona walks out in disgust.
In Can't Tell Me Nothing (2), Fiona confronts Katie for stealing her coffee house idea, and calls her a lazy loser.
In In The Cold, Cold Night (1), Fiona is gossiping to Imogen about Katie being in rehab.
- They both went to rehab.
- They were both love interests of both Torres brothers, although Fiona was more interested in Adam, while Katie was interested in Drew.
- Katie also had a conflict with Fiona's girlfriend Imogen while Fiona also had a conflict with Katie's best friend Marisol though she ended it with her.
- They both had a spring fling - Fiona with Charlie Lima in season 11 and Katie with Darrin Howe in season 12.
- Dallas has had a crush on both girls and weren't interested in him.
- Fiona planned Drew and Bianca's wedding. Two people that Katie hate.
- Fiona is roommates with Katie's ex-boyfriend Drew.
- Fiona planned the wedding of two of Katie's enemies Drew and Bianca
- Both were at Drew and Bianca's "wedding" in Vegas.
- Katie shares a lot of similarities to Fiona's best friend Holly J
- Both are overachievers.
- Both have/had red hair.
- Both were Student Council President at some point.
- Both had health issues.
- Both are or at one point were on Student Council.
- Mike Dallas had a crush on each girl although it was unrequited.