Arts and Crafts workshop for children

I need someone who can keep about 25 children of varying ages (up to 12 years old) entertained doing arts and crafts, painting, etc for 2 hours on Saturday March 17 between 2.30pm - 4.30pm in Bolton (BL1 1HA).
Their mums will be in the next room but the kids need to be kept busy so the mums could focus on their meeting (community group event).
Art workshop or anything that would not involve too much noise is preferred because of the meeting.