Gwyneth Paltrow is an actress down to her toes, as she proved Wednesday night at the London premiere of playwright David Auburn’s Pulitzer Prize-winning Broadway drama “Proof,” reports Reuters. In it, she plays the shoeless and troubled daughter of an eccentric math genius. “It is not often one gets to see anyone acting with their feet. Ms. Paltrow manages it however,” wrote critic Valentine Low of London’s Evening Standard. “In the first few scenes she is wearing sandals and manages to use her toes to express annoyance, frustration, unhappiness and a whole range of emotions that some actresses cannot manage with their faces, let alone their feet.” High praise, indeed. Reuters also tells that Paltrow’s parents, director Bruce Paltrow and actress Blythe Danner, were part of the opening night audience. Fans stood outside the theater hoping for a glimpse of the “Shakespeare in Love” Oscar winner, 29, but they were out of luck. Paltrow was in her dressing room well before the performance, says the news service, which also notes that her limited run (through June 15) is completely sold out. Meanwhile, back on Broadway, Jennifer Jason Leigh, 40, who replaced the original, Tony-winning star of “Proof,” Mary-Louise Parker, is about to be replaced herself. (Leigh took over for Parker the fateful week of Sept. 11.) Variety reports that Anne Heche, 33, is negotiating to step into the role that Leigh leaves on June 30.