A: Once when you tell it once when you tell her the punchline and once when she gets it.
Because telling them once wasn't enough.
She would call you at least 1000 times to tell how sorry she is .
Barns and no-bulls. (This joke was made up by my 7 year-old cousin.)
Boo man! Boo!
Life
The punchlines were too long.
Tell her a joke at Christmas
Three times - Once when you tell it, once when you explain it, and once when she gets it.