As it ends its second theatre run in London, it's being broadcast live in cinemas globally.
A far cry from her pop star or Doctor Who days, it's an intense performance about a woman struggling to have a child.
It's the role which has won her five star reviews and a Laurence Olivier award.
With a massive smile on her face she says "it's a really prestigious award" - essentially the theatre version of an Academy Award or a Bafta.
