Ella's mother and Dame Olga
We only have one chapter to get to know Ella's mom before she dies, but we get the sense that she's pretty chill. She rarely gives Ella orders, instead spending a lot of time with Ella doing fun things like swimming and telling each other stories. She's also not terribly concerned with etiquette, since Char recounts how once she made a napkin into a caricature of a boring chancellor.
Dame Olga is the exact opposite: she's obsessed with status and wealth, and it's pretty clear from Olive's desperate need for human contact that she was a neglectful mother.
Mandy and Lucinda
Mandy, like most other fairies we meet or hear about in the novel, tries to lay low and not let humans know about being a fairy. Lucinda prefers flashy entrances and exits, and she uses magic to modify her appearance, looking beautiful and young when Ella meets her at the giant's wedding. Mandy also spends her life serving and aiding the humans she loves (the Eleanors of Ella's family) while Lucinda flits about from wedding to birthing, bestowing unwelcome and destructive gifts.
Until Lucinda gets a taste of her own medicine, they seem to have nothing in common apart from being of the same magical species.