Big brother: That planet up there is Mars.
Little sister: Then that other one must be Pa's.

Why did your sister cut a hole in her new umbrella ?
Because she wanted to be able to tell when it stopped raining.

Father: Why did you put a toad in your sister's bed ?
Son: I couldn't find a spider.

Did you hear about the sister who wrote herself a letter and forgot to sign it and when it arrived she didn't know who it was from.

Did you hear about the boy who saw a witch riding on a broomstick ? He said, 'what are you doing on that ?'
She replied, 'my sister's got the vacuum cleaner.'

Why did your sister shoot the alarm clock ?
Because she felt like killing time.

Witch: Doctor, Doctor, my sister here keeps thinking she's invisible.
Doctor: Which sister

Why did your sister separate the thread from the needle ?
Because the needle had something in it's eye.

Why did your sister wear a wet shirt all day ?
Because the label said, 'Wash and Wear.'

Why did your sister spend two weeks in a revolving door ?
Because she was looking for the doorknob.