Section 4B. The department shall continue to provide assistance to families who are otherwise eligible for such assistance under the provisions of section two and who are temporarily making their residence at the New Chardon street shelter in the city of Boston administered by the department of children and families. Said department of children and families is further authorized and directed to establish a sliding scale system of fees for the provision of temporary housing services at the New Chardon street shelter in said city of Boston. The fee under such system for a family receiving benefits under said section two shall not exceed the food and shelter component for such benefits as established by the department of transitional assistance.