I doubt she was a sex worker, at least not originally planned. She looks very Eastern European (Russian, Polish, Ukrainian, Belarussian) to me and several articles mention she was an Eastern European hitchhiker.
She likely was an immigrant, possibly undocumented, fled the Iron Curtain somehow and then working odd jobs in Britain that were not prostitution but maybe maid in a hotel, cleaner, dishwasher, farmworker. She may have been forced into prostitution occasionally but i doubt she was a prostitute.
Her poor dental health reflects her inability to access NHS healthcare and many Eastern Europeans back in those days made their own clothing, especially if they were poor. Her style of clothing is very 1960s/70s instead of 1982, another indication she came from Eastern Europe that somehow used to lag behind a decade fashionwise.
I wonder how she managed to get to the UK from whereever she came from. It was absolutely not easy to flee the Iron Curtain back then but many succeeded.