なお、担任の白鳥しらとり先生は、未だに教卓で涙を流している。ちなみに、担任はこのクラスが初めてという女性教諭である。 Need help with the part in bold. Does this mean that this is her first class as a 担任? p.s. welp I still don’t get は and が
Furthermore, Shiratori-sensei, the homeroom teacher, was still in tears at the teacher desk. By the way, the homeroom teacher is a female teacher that has had this class as her first one. ETA: this means that this is the first time she's in charge of a class as a homeroom teacher. Also, "wa" is a topic marker that often, but not always, coincides with the subject (but depending on the emphasis, it may replace other particles, like "wo" or "ni"), while "ga" is mostly either the subject marker (if it's not "a" or it's a subordinate sentence), the core marker of nominal sentences, or "but". ETA2 (JIC): @Hasr11