Yes, and in JA’s world, it was the sole ‘career’ available to women of her class, the alternatives being being kept by male relatives after the death of your father (as JA and her sister and mother were for years, living in a perpetual round of lengthy ‘visits’ to family members, and which is what Charlotte Lucas is facing when she leaps at the chance to marry an idiot with decent prospects, only her younger brother is already moaning about having her left on his hands), genteel poverty in a couple of rented rooms like Mrs and Miss Bates in Emma, or Mrs Smith in Persuasion, or governessing like Jane Fairfax plans to in Emma (if sufficiently well-educated/accomplished).
She knew about women’s poverty, and economics is always at play in her romances.
I mean, supposing none of the Bennet girls married well before Mr Bennet’s death, they’d have been living in a few rooms above a shop in Meryton, on their mother’s tiny income, their marital prospects much reduced, and while Jane might have made a decent governess, or Lizzy, or, at a pinch, Mary for a family that wasn’t concerned with her teaching their daughters social ease and etiquette, just music and academic subjects — no one would have employed Kitty or Lydia.
Emma is fortunate to be so financially secure she can look on marriage only as something she would consider only were she to fall in love. Even Fanny Price is essentially threatened with a life of poverty as punishment for refusing Henry Crawford.