DD3 is Mary in the school nativity 
DD1 was an angel
DD2 was a christmas bauble.
I'm not sure what DD3 was meant to be, but when 'Mary' burst into tears and said she'd rather be an angel, DD3 approached the teacher and said 'I'll do that thing...whatever it is.'
A bit of debate ensued between the two Yr R teachers, because DD3 is in the class that the 'Joseph' was chosen from, and 'Mary' was from the other class, so the other class teacher felt that it really should be one of her girls.
Apparently, DD3 walked up to them as they were debating and said 'you know that thingy...whatever it is....I will do it, you know....'
They decided she'd earned the role for having the gumption to offer herself twice 