Her mother told her, 'God sent you.'  

'Did God send you, too?' asked the child.  
'Yes, Dear,' the mother replied.  

'What about Grandma and Grandpa?' the child persisted

'He sent them also,' the mother said.  
'Did he send THEIR parents too?' asked the child.  

'Yes, Dear, He did,' said the mother patiently.

'So... you're telling me that there's been NO sex in this family for 200 years?
No wonder everyone's so grouchy around here!