"why is looking after a bunch of screaming babies and living in a little flat all on her own on some shitty council estate, the very best thing that a young working-class girl with her whole life ahead of her, imagines that she can aspire to achieve?"

No takers? Well I'd say because unfortunately, particularly in very depressed areas, it might possibly actually BE the best thing she can aspire to achieve. Unless she's an exceptionally self-motivated and intelligent individual, consider the likely alternatives: leaving school with a handful of useless GCSE's (no-one can afford a degree these days anyway) privately renting at today's ridiculously inflated prices (no-one can afford a mortgage these days either) and working some crappy minimum wage job... (oops, can't pay the rent on that low income).