There’s been a very courteous, very passive-aggressive skirmish unfolding over social media recently about which former Condé Nast veteran was the true inspiration for Emily Blunt ’s scene-stealing first assistant in The Devil Wears Prada — Emily Charlton — who, of course, returns in the sequel. In one corner, there’s celebrity stylist Leslie Fremar , who served as Anna Wintour’s real first assistant at Vogue back in 1999, the same year Lauren Weisberger, author of the best-seller on which the first movie was based, served as Wintour’s second assistant. “It was really based off a lot of things that, you know, I lived, she lived,” Fremar said recently on Vogue ’s podcast The Run-Through , noting that, like the Emily in the movie, she was “not very nice” to Weisberger back when they worked together. But not so fast, Leslie. Because the internet is also bristling with speculation that Vogue ’s longtime entertainment director-turned-casting director Jill Demling is actually Emily’s true inspiration.…