If you think about it.
One of them died on a bombing and the other one is in coma.
They are in russia or some cold northern country that i have never knew about.
The girls get comatosed and dream of marrying the boy thus the boy is older and she is not.
she wants the boy to grow up and then here you go.
she cannot imagine/dream of the ring cause the dream would end if it has a gem on it.
The girls dream is to get married. she only get half married cause the ring is still in half.
Or just vice versa.
The boy in coma. want's to fulfill their wedding promise.
He wanted to give her the world
So in his dream he give her the world and marriage.
PS: they do not have a son or daugther cause children does not think of sex. they just think of love... and staying together with the ones you love.