I'm looking for a novel with the 'daughter of a wealthy family gets swapped as a child' premise, but with a twist - the protagonist is the 'fake' daughter that was raised in the wealthy family. She goes back to living with her biological family, who she initially has a rocky relationship with but grows to care for. There was definitely a rebirth/transmigration element which I realize does not narrow things down in any way.
I suspect there's more than one book matching that description, but it might have been this one? https://www.novelupdates.com/series/fake-villain-turned-into-cannon-fodder/ The family relationships on the whole go fairly smoothly since the (transmigrated) heroine is more mature than her apparent age and able to put up with their shenanigans pretty calmly, but her 'new' family certainly present their share of problems... The fact that they're much more flawed and complex than the usual 2D supporting characters was what I really liked about this book.
Sadly you are right in that there must be more than one book matching my description - this wasn't the one I remember reading. Thanks for the rec!
For anyone who was curious, it turns out the novel I was looking for was "Sweet Finale to a Lifetime of Quick Transmigrations". It seems that I'd remembered a *lot* of the details wrongly.