I'm disappointed that the following vignette was not in the movie.

While visiting the United Kingdom , Winnie Mandela was invited to a cocktail party which was also to be attended by Margaret Thatcher.
When Winnie saw the ex-prime minister on the other side of the room, she barged past everyone, spilling the drinks of several invited guests on the way.
Winnie elbowed her way to Maggie, stood brazenly in front of her and declared,
"I hear they call you the Iron Lady!"
"I have been referred to by that name, yes," replied Maggie, peering down her nose at this impudent upstart.
"And whom, may I enquire, do I have the honour of addressing?" asked Maggie icily.
"I am the iron lady of South Africa !" bragged Winnie, waving her fist in the air.
"Oh, yes," replied Maggie dryly. "And for whom do you iron?"