Money was always pretty short, but the Austen parents were hardworking and enterprising - in the early years, as well as Mr A's clergyman's stipend, they farmed and ran a small boarding school for boys in their house and produced pretty much everything they ate and drank themselves - so they probably didn't really take part in a cash economy a lot. (Mr A was gentry, Mrs A was from a family of minor aristocrats, the Leighs, which doesn't seem to have stopped her getting her hands dirty.)
Then Mr A decided to retire and they moved to lodgings in Bath with Cassandra and Jane, the two girls at home.
But after Mr A died suddenly five years later, Jane, Cassandra and her mother were left in a pretty insecure position, and spent the next few years essentially living in temporary rented lodgings, combining living with another spinster friend Martha Lloyd and with her naval brother Frank's wife while he was at sea, and doing long visits to family members, which sounds pretty grim. There are various stoical bits in her letters about waiting for it to be convenient for some other family member to come and pick them up and get them to a different household.
Then the Austen brother who'd inherited from rich cousins, Edward, offered them a cottage he owned in a village on the estate. Even then, when the eldest brother Henry's bank failed, meaning lots of the family lost money, Frank and Henry couldn't afford the contributions they'd been making to the upkeep of J, C and Mrs A, and J wasn't making that much money as a novelist, even from her most successful novels.
I think all that really informs JA's portrayal of women like Charlotte Lucas, or Mrs and Miss Bates (the widow and spinster daughter of the vicar, now poor and living in rooms over a shop), or Jane Fairfax, an orphan with no fortune who is about to become a governess when Frank Churchill marries her - or, at a rather grander level, the Dashwood women (who, admittedly, have also fallen further, socially).
She's very aware, not to much of 'marrying well', but the very narrow limits occupied by poor women who don't marry, or are widowed - total reliance on male family members' goodwill (and their good luck), drifting down the social scale, not having a home of their own etc.
It's one of the most interesting bits in Emma, that when Harriet Smith asks whether Emma will never marry and won't it be awful to be an old maid, Emma's response is completely in terms of economics and social importance. She says that being a poor old maid would be awful, but that with money no woman is ridiculous, and that she could never be of more importance to any man than she is to her father, so she doesn't need marriage!
I assume we're supposed to see that partly as a sign of her immaturity and self-satisfaction, but it's an interesting point of view if we think of her books as love stories. Marriage and money are always intertwined.