Using an A4 sheet of paper create a birthday book of all leaders and Brownies birthdays
Fold A4 paper/card in half and in portrait view draw a big tiered birthday cake with candles on the front, colour in. Also write 'Brownies Name's Birthday Book.
Split each further page into 4 and write the 12 months.
Let each girl go around collecting birthdays.
Time taken depends on size of group