I've just watched it on the IPlayer. Ruth Negga played the part of Shirley really well. A lot of people were living on the poverty line in those days, but one can understand the urge Shirley had to get out of it.
The actress Lesley Sharp played a good part as her Mother, her Mother incidently put it about a bit,

but that's how a lot of peoples lives were.
Strangely enough Shirley married Kenneth Hume twice, but from a young age and beyond, she remained very vulnerable.
It did end abruptly though.