Unless a woman has done something absolutely abhorrent along the lines of murder/child abuse/caused life changing injuries, prison shouldn't be the answer. I am not sure if I remember correctly but I think this woman had committed robbery, and she was known to social services as a vulnerable person since birth and had been a victim of exploitation.
Pregnant woman should receive the maximum sentence for their crime, without prison, such as being on a tag, physically appropriate community service, a fine, rehabilitation programmes, whatever it may be to ensure they feel the full effects of their law for their crime.
But putting a vulnerable, young, mother to be in a prison cell was absolutely not necessary in this case.
Those involved should feel deep shame and not be allowed to work with vulnerable people again.