It appears there may be some inaccuracies in your statement.
Firstly, Lady Gaga is an American singer-songwriter and actress, but I couldn't find any evidence that she was involved in the filming of 'The Devil Wears Prada 2' in Milan.
Secondly, 'The Devil Wears Prada 2' is not a confirmed sequel to the 2006 film 'The Devil Wears Prada', starring Meryl Streep and Anne Hathaway. There have been reports of a possible sequel in development, but I couldn't find any information that confirms Lady Gaga's involvement.
Lastly, while Lady Gaga does have a global presence and has been involved in various projects, I couldn't find any information about her filming a project in Milan.
If you have any more information or clarification, I'd be happy to help.
