This one is in response to Elvira's challenge:
My sister Mathilda was not a bad sort,
She didn't wear make up, her hair was quite short.
She couldn't be bothered with little-girl toys,
Mathilda was almost one of the boys
But sister Mathilda just lately has changed;
I rather suspect she's becoming deranged.
She doesn't come out when I want to play ball,
Not like my sister Mathilda at all!
She says she's grown up, that she's started the curse,
Not sure what that is, but her temper is worse.
I consulted my dad, this answer gave he,
"Don't be surprised, boy, Mathilda's a she."