A transgender student fighting a legal battle for unfettered access to the girls’ locker room at her school has enlisted some help at the appeals court. More than 20 civil rights, medical and LGBTQ groups have filed three different friend-of-the-court briefs in her case, now pending at the 1st District Appellate Court. A Cook County judge had denied a request by the student, a senior in Palatine-based District 211, for a preliminary injunction allowing her to use the girls’ locker room. The judge concluded the …