Jenna and Sadie have always been enemies prior to the start of the series. It is hinted on numerous occasions that Sadie is jealous of Jenna because Matty loves Jenna and not Sadie. Sadie bullies Jenna and usually makes fun of her. Despite this, Sadie appears impressed when Jenna stands up to Eva.
Jenna and Sadie have an antagonistic relationship which has hinted to have always being antagonistic prior to the series as Jenna volunteers for Jake Rosati's prep rally as an attempt to get closer to Matty McKibben. There task involved in both pairs swapping each others clothes and the fastest wins, which Jenna and her partner wins because Sadie couldn't fit into Matty's clothes. When Jenna finds out about this she tries to apologize to Sadie, who is convinced that Jenna picked the sex exchange game on purpose to embarrass her.Sadie and her best friend Lissa Miller decide to get "revenge" on Jenna for her sex exchange task and snap a nude photo of Jenna's breasts in the girls' locker room and send it to the entire school. The school's counselor, Valerie Marks talks with Sadie and Jenna about the picture, but Sadie manages to manipulate her way out of trouble, much to Jenna's protests claiming that the photo is illegal since she is underage.
Jenna takes Tamara as her plus one to Lissa's party and is immediately insulted by an angry Sadie who asks "who the fuck invited you". Later on, she tells Jenna to play with "the blood violin", making a reference to her misunderstood failed suicide attempt.
Jenna is forced by her mother into joining a knick-knacker intake gathering, where she discovers that Darlene Saxton is Sadie's mother and Sadie herself gave Jenna a nametag saying "SKANK". Tamara and Jenna become convinced that Sadie wrote the care-frontation letter after she quoted a line and go up to Sadie's bedroom, where they find Sadie's dietary diary, which they take and Tamara tries to convince Jenna to blackmail Sadie with her secrets. In the end, Jenna insults Sadie with the help of a diary entry, but Sadie gets her back, by convincing her that the next knick-knacker event is a formal one, when it a casual-wear one, embarrassing both Jenna and her mother when they appear at a soup-kitchen dressed nicely. Jenna also asks Sadie about the letter, which she has no clue about, saying that she likes to make her insults in public.
- Despite their characters being enemies, Ashley Rickards and Molly Tarlov are actually friends in real life.
- Both characters have brown hair, brown eyes and have/had a signature necklace.
- Jenna used Sadie's catchphrase, "you're welcome" in Queen Bee-atches.
- They both first meet each others mother's in Queen Bee-atches.
- Sadie began to take notice in Jenna's relationship with Matty in Queen Bee-atches.
- It is suggested in Queen Bee-atches that Sadie is Jealous of Jenna.