Ollie and Dawn are a pair of step cousins and they work with each other a lot. This frustrates Arlene, due to her father's rivalry with Dawn's father, so she does everything in her power to destroy the vibe. Although at the end of the first season, Dawn tries to find Wanda and goes in her house with Ollie (they were invited because it was a free party) and Arlene actually danced with Ollie. But she does show signs of tolerance for Dawn because of her father forcing her to hate dawn .
Arlene barely knew her mother, Trixie, due to her having passed away after Arlene's birth. Because of this, Arlene considers her fairy godmother, Blonda, the closest thing she has to a mother. Trixie's death doesn’t have any impact on the show though but it’s a fact that makes Arlene a bit more understandable than without the fact.
Arlene has a small crush on Ollie Skylark.
Dawn can't really stand up to her because of how much of a prick Arlene is to her.