The answer to the question: What town did Jenny want her parents to think she was in? is inside the article: Lancashire mill-girls Jenny Hawthorne and Mary Hollins go on holiday to Blackpool during the annual wakes week in their hometown of Hindle.  They run into Alan Jeffcote, the son of the owner of the mill in which they work, who has also traveled to Blackpool with a group of friends while his fiancée is detained on business in London.  Jenny and Alan hit it off immediately, and he persuades her to leave Blackpool to spend the week with him at Llandudno in North Wales.  To cover her tracks, Jenny leaves a postcard with Mary, asking her to send it to her parents (Edmund Gwenn and Sybil Thorndike) later in the week.  She and Alan leave their friends and set off for Wales. Shortly afterwards, Mary is involved in a serious road accident and is killed.  Her possessions are returned to Hindle and the unmailed postcard is found in her luggage.  Jenny's parents are already suspicious and concerned by the fact that Jenny has not returned to Hindle as they would have expected in view of such a tragic turn to her holiday, and the discovery of the postcard increases their fears.  Jenny returns at the end of the week.  Her parents ask about her holiday, and allow her to dig a hole for herself as her fictitious account shows she is unaware of Mary's death and has clearly not spent the week in Blackpool.  When confronted with the truth, Jenny admits to where she has been, and with whom, and defiantly refuses to be made to feel guilty or immoral., can you guess it ?
The answer to this question is:
Blackpool