Elsie Frost was 14 when she was attacked close to the Calder and Hebble Canal on October 9, 1965.
It is thought she had been walking home from an afternoon sailing with her friends at what is now known as Horbury Lagoon, when her killer struck.
Despite a huge manhunt, the case remains unsolved and last week West Yorkshire Police made a new appealed for information.
A memorial service was due to be held on Friday afternoon at the ‘ABC’ railway service steps where Elsie’s body was found.
Meanwhile officers from the Major Investigation Review Team are evaluating new information received since last Friday’s appeal.
In a statement, Colin Frost and Anne Cleave, Elsie’s brother and sister, have said: “We are extremely encouraged by the responses already received from the public following the new appeal made last week and it is our hope that this will continue.
“We still have many unanswered questions and we will therefore continue to pursue the answers to those questions. It is our hope that this information will lead to us getting justice for Elsie after all these years.
“Elsie remains never forgotten and always remembered.”
Detective Chief Inspector Elizabeth Belton, of the Homicide and Major Enquiry Team, who is leading the new enquiry, said: “We have been delighted with the attention the new appeal received and are very encouraged by the calls and emails which have come in so far offering information.
“Every new piece of information will be looked into and we are continuing to progress the lines of enquiry we identified in our appeals last week.
“We continue to work to identify a white man on a bike who was seen near the murder scene on the day of the murder. He was aged 25 to 30 years-old and was riding a black bike with a basket on the front and wearing a white lab type coat possibly of the style then worn by someone who could have been a delivery boy, butcher or abattoir worker.”
Police want to speak to anyone who attended Balne Lane Youth Club in 1965.
Ms Belton added: “With the anniversary of Elsie’s death upon us our thoughts remain very much with Anne and Colin at this time, as I’m sure many others are in Wakefield. Elsie was a much loved, bright and vivacious girl who was clearly adored by her family. For 50 years now, they have had to live with the knowledge that the person who killed her has escaped justice, but now have the hope that person may finally be identified.
“We are determined to do all we can to make that hope a reality.
Call HMET via 101.