Is it canon that beth and annie's mom was depressive that their dad left and they had no money growing up ? I don't remember hearing about it on the show but read it on your fics. How much do we know about their childhood and when did we learn it ? Thank you :)
It’s not canonically confirmed, no! It’s just an inference—or a logical conclusion compiled from evidence.
I use the 2.08 flashbacks as the main source of my inferences:
The other flashback scene we get is Beth and Ruby sitting on a bench outside of Ruby’s father’s funeral. Beth asks Ruby if she wants to go in, Ruby says no because it’s “going to be weird,” and Beth says, “He was your dad,” before she rests her head on Ruby’s shoulder to comfort her.
Taking all of that into consider, I infer:
Because Beth is driving too young and doing something reckless, I assume she feels that the errand is necessary
Because Beth is buying groceries, I assume Beth has taken over her mother’s responsibilities in feeding and raising Annie
Because Annie claims her mother “likes” to spend a lot of time in bed, (showing that she doesn’t have a clear reason to do so that would make sense to a child, such as a physical illness or injury), I assume it is probably a mental illness or emotional breakdown of some sort.
Because there is no reference to their father—either an excuse or reasonable justification for why he couldn’t buy the groceries in Beth’s place—I assume he is not around
Because they show us a funeral scene with Ruby’s father and because Beth doesn’t personally relate to it by sharing her own experience, I assume Beth’s father is not dead
In 2.10, Ruby and Annie fight:
ANNIE: Just because I didn’t choose some safe-ass, boring-ass life like my sister—
RUBY: You know why she did that? Because she had to. She didn’t have anyone to clean up after her like you do.
ANNIE: That’s not true.
RUBY: She has been mopping up your messes since the day I met you.
This confirms the inference that Beth has been mothering Annie since Beth was a teenager, and suggests that this was not a type of mothering she herself received since nobody was “clean[ing] up after her.” In that vein, the fact that Ruby says she “had” to choose a “safe” and “boring” life suggests that Beth’s own upbringing was somewhat unstable. Though its still wide open for interpretation in terms of severity, it does help us understand why she stayed—and why she stays—with Dean, who really does represent safety and security across the series despite the fact that the show starts with this illusion being shattered. This is why her reaction to Dean’s reckless handling of their finances—and its consequences plunging them into utter instability—is so extreme.
From there, I’ve just played around with details of Beth’s backstory in my fics to flesh out the world from the inferences I’ve made!