Here we are together! She was wearing very high heels. And my face doesn't look as fat as that in real life! And I'm not quite as horsey!
I will give a full debrief later for those who are interested in the backstage tour etc!
(The only thing she really said to me was "I love your accent, enjoy the show"). 
Many thanks to all who made wardrobe suggestions. In the end, I went for this top (from Tesco!), dark bootcut jeans, sparkly silver heels and sparkly silver nails.