Mum is gluing something together and using clothes pegs to hold the bits together.  Clothes pegs are one of the versatile unsung heroes of crafting,  Dolly pegs can be used to make peg dolls with, I suppose the clue is in the name.  The springy ones apart from holding gluey things together, can be painted,  decorated, have a bit of magnet attached and hey presto can be used to hold notes on the fridge.  They would make a project for a child to decorate as a Christmas stocking holder.  Some people even use them for hanging out their washing.