I am an academic in just this sort of field (a foreign language/literature) and we always have a few mature students in every BA/MA/PhD cohort - typically either women of 40+ or men or women who have recently retired. They are usually very good. Two of my current PhD students are women in your sort of position - one has grown up children whom she'd been at home with; the other has quite a young family and is switching from a previous career.
You certainly shouldn't assume that you'd get a job out of it at the end, but you shouldn't completely rule that out either - though it's also worth thinking fairly seriously whether you would actually want all the pressures of e.g. a junior lecturer job in your mid-40s. (And would you/could you move around? Your options will be a lot more limited if you have no mobility for family reasons, a bit less so if you're somewhere like London with quite a few universities within commuting distance.)
In any case, a higher qualification in a modern foreign language might open other doors too - teaching more generally (if it's a reasonably mainstream language) or translating/interpreting, if you make a point of working on your language skills alongside the literature. Also, in language teaching there are always quite a lot of sort of 'para-academic' jobs around - e.g. doing language teaching for university departments or for university language centres. These sorts of jobs may not be as well paid as a permanent academic post, but they come without the constant research/fundraising pressure as well, so might be attractive if you find that you enjoy teaching the language/languages you study.
Also, it is possible (though not at all easy/common) to get funding for graduate study. It is usually hardest to do so at MA level, but if you really excelled in your BA or go on to do very well indeed at MA there's at least a chance of it. Studying part-time can sometimes be a slight advantage here I think, because by Christmas of the second year of a part-time MA course, for instance, you'll probably already have some concrete grades, whereas half-way through a full-time MA, when students apply for PhD funding, they have often had nothing marked yet, or perhaps one piece.
I would suggest you get back in touch with your BA tutors and arrange to discuss this with them; you can also ask around and try to find out whether any academics, post-docs or PhD students at your institution came into academia as a second/later career.