Oh yes my SIL is fabulously bonkers.
She refused to visit us in our first house because they lived in a flat and she couldn't bear it.
Came to my 'black tie' 30th dressed in a tracksuit with a beanie hat on and unwashed hair (she's the type to wear full makeup and accessories to go to Tesco, usually).
Wouldn't come to the spa part of my hen do because she couldn't afford it (£60) but came to the evening do and told everybody several times that her new top had cost £60. When we did a group photo she stood up and turned her back.
Didn't want her DS to be our page boy as he wouldn't want to wear a suit. Brought him to the wedding wearing a suit, and eating a cornetto all the way through our vows.
Heckled the speeches and then announced her recent miscarriage to the room.
Then cornered me for an hour on the balcony while she cried about how terrible her life is.
She has mellowed in the last ten years but is still batshit.
And I'm the one with the MH issues! 