books that involve immediate family members who are of a different social class

[Tdr85]

Usually this would occur either through adoption or remarriage. Examples would be a mother who remarries into wealth but the kids remain with the poor dad or shuttled into some other arrangement, or vice versa; adoptee's family is wealthy or poor (or even middle class) while the birth parent are the reverse. Either the family is aware from beginning or discovered during the story. It plays a significant role in the story. Prefer contemporary.

[Kiersten]

This isn't the most nuanced treatment of the subject, but the first thing that comes to mind is Kristy's family in the Babysitters Club series (Babysitters Club Collection #1). Her mother remarries a few books in, and her stepfather is extremely wealthy (Kristy's family was previously middle class)

[Spockles]

If you like YA, The Wrong Side of Right by Jenn Marie Thorne, the heroine finds out she has a dad who is a wealthy senator running for presidency. She joins him on his campaign tour for a few months as she tries to decide whether she wants to get to know him or keep living with her aunt and uncle.

[Ann aka Iftcan]

This is more a mg (middle grade) or YA book, and it's about a girl who has 2 adoption options, and how, after a summer spent visiting each option has to pick where she will live. One of them is a very wealthy single woman, the other is a middle class farm family. Adopted Jane.

The Headless Cupid has this to a certain degree. The step-sister's father (I think it's her father) is a famous director or actor (it's been a decade or 2 since I read these these) and the Mum has married into a middle-class family. There are 4 or 5 of these books. They are MG or tweenie type books.

[Pamela]

Not contemporary, but the Her Royal Spyness series of mysteries by Rhys Bowen involves a situation like this. Protagonist's grandfather is a retired London policeman whose daughter married a duke. Starts with Her Royal Spyness. Her Royal Spyness

[CraftyChara]

Cocaine Blues

[Ann aka Iftcan]

Ooh, that's a good one Cara. It's also not a "contemporary" since it's set in the 20's but it's a good one Tdr.

[CraftyChara]

Ann aka Iftcan wrote: "Ooh, that's a good one Cara. It's also not a "contemporary" since it's set in the 20's but it's a good one Tdr."

Thanks and whoops. I admit that I only read the title. ^^"

[CraftyChara]

The Orphan Keeper Indian caste system
China Rich Girlfriend
The Power of Two Alex poor twin Cam rich twin
Magyk

[Rosa]

Bella at Midnight

[Pamela]

Tiffany Sly Lives Here Now by Dana L. Davis Tiffany Sly Lives Here Now

[SamSpayedPI]

Really not contemporary, but Little Lord Fauntleroy.

[Ebookworm2016]

Well, I’ve only seen the movie, but it’s based on a book:
“Crazy Rich Asians” by Kevin Kwan.

[Rosa]

Crazy Rich Asians for the link.

[Lobstergirl, au gratin]

Tono-Bungay

[Ann]

Chesapeake Series 1-4 by Nora Roberts
One Perfect Rose by Mary Jo Putney - historical but I'm suggesting it anyway.

[Lobstergirl, au gratin]

The History of Henry Esmond

[Lobstergirl, au gratin]

A Girl Returned

[Lobstergirl, au gratin]

The Living Sea of Waking Dreams