In Summertime, Frankie and her twin brother Hunter are mentioned by their father when he asks Miles why he can't act more like his siblings.
In You Got Me, Zoë tells Frankie that she has a date to the Beach Bash and Frankie hopes that it's not her brother. Miles then goes up to the two of them to buy tickets to the dance and greets Frankie. He then criticizes her for being friends with Zoë.
In No Surprises, Miles and Frankie are seen with their whole family at their home. Mr. Hollingsworth praises Frankie and Hunter in front of Miles. They're also seen being interviewed by their father's campaign manager.
In Basket Case, she attends Miles's party. The next day, she sits by as he cleans the pool, and tells their father that Miles was telling the truth.
In You Are Not Alone, Miles points out that the girl that Winston Chu was attracted to at his comic book stand was his little sister, Frankie. Later, when Winston comes to the Hollingsworth house to confront Frankie, Miles is amused and comments that he was going to make popcorn to watch this. However, while he was gone, Frankie and Winston end up kissing, which they agreed that Miles could not know about.In Enjoy the Silence, Miles interrupts Frankie and Winston's conversation, saying that Frankie's best friend Keisha tweeted about how Frankie made out with someone. Miles is determined to find this guy and give him a warning. Winston is forced to act like he doesn't know anything and joins Miles's search to "find" the guy who kissed Frankie. Winston later admitted to Tristan Milligan that he is the one who kissed Frankie, but doesn't want to tell Miles because he will be angry with him. Tristan realizes that Winston actually has feelings for Frankie, and calls Miles, saying that Winston knows who kissed Frankie. Later, Miles figures out that Winston is the one who made out with Frankie, and finds it hilarious since Frankie has had a crush on him since she was eight. He, however, thinks that Winston and Frankie will not end up dating.
In Out of My Head, Frankie and Miles walk in the hallway, and Frankie tells him that everybody is making fun of her because she's rich. Miles asks her why she cares what everybody thinks, and Frankie tells him that everyone thinks their mom paid Becky to let her be a model. She asks if their mom ever paid someone so that Miles could be on a team, and he reveals she previously paid the coach so that he could stay in the baseball league.In Thunderstruck,Winston and Frankie are cuddling on the couch while watching TV, before Miles steals the remote and changes the channel. Frankie attempts to get the remote back by jumping on Miles's back, and they all decide to play a game of charades for the good TV. Miles and Frankie are both very competitive at charades, however, Miles and Tristan seem to make a better team than Winston and Frankie. During the game, Grant Yates is mentioned when Miles calls him a creep, and Tristan is confused because he had a relationship with him. Winston reveals that Grant tried to grope him, and Tristan comments that he would never do that. However, Winston, Frankie, and Miles realize that Tristan had a relationship with him. Later, they all decide to play the game.
In My Hero, it is revealed by Becky that she and "Sir Excellence" both have mean older brothers. Hunter himself later tells Becky that real world people always disappoint (most likely referring to his family) and that's why he plays Realm of Doom.
In Smells Like Teen Spirit, Miles enters the family lunch and he discusses with his parents the boyfriend relationship, which they really don't approve of. Miles mocks everybody except Hunter by saying that it isn't "ridiculous" to kiss somebody. Frankie asks if Tristan and Miles are a couple, Miles says maybe and she asks if he is gay, bi, or experimenting with fluid sexuality, Miles shrugs in response. From this scene, it appears that Hunter has never kissed a girl. Hunter responds to Miles, "Suck it." and then listens to music with beats.
In Wise Up, Miles comes home in a rage after having yet another fight with his father and Frankie and Hunter are both sitting by the window. Frankie tells him that he's just like their father and starts half of the fights they get into. Miles doesn't want to believe this and runs off.
In If You Could Only See, Hunter walks in on his sister and Winston fooling around in bed with his brother and mother right behind him. He acts uncomfortable and can't look her in the eyes after. Mrs. Hollingsworth tells Winston he has to leave and then tells Frankie she cannot have boys in her room anymore, much to Frankie's disliking.
- Frankie was best friends with Miles' ex-girlfriend, Zoë Rivas.
- Frankie does not seem to approve of Miles and Zoë's former relationship.
- Miles doesn't seem to like the friendship between Frankie and Zoë Rivas.
- Winston, Miles's best friend, began a relationship with Frankie, which they wanted to keep secret from Miles. However, Miles now knows about it.
- They both had dated each other's best friend.
- Miles dated Frankie's former best friend, Zoë and Frankie dated Miles' best friend, Winston.
- In Thunderstruck, we learn that Miles and Frankie tend to battle things out in charades.
- In Firestarter (1), Miles reveals that he knows when his sister is lying.
- Miles got Frankie's best friend Lola Pacini pregnant, but she terminated the pregnancy.
- Zoë: "I want to look good for my date."
Frankie: "Your date? Who are you going with? Better not be Miles. Don't you dare take my stupid, older brother back." - You Got Me
- Zoë: "Since dumping your ass I've found my girls." (referring to Frankie and other girls)
Miles: "Seriously, sis? I thought you'd have a better taste in friends." - You Got Me
- Miles: "Look, Frankie. I know high school guys. Okay, I am high school guys. We aren't nice. He needs a warning. Right, Chewy?"
Winston: "Um, you usually hate your sister."
Miles: "That doesn't mean I want some grade 10 or 11 creep trying to feel her up! She's in grade 9!" - Enjoy the Silence