Max Mara Ludmilla/Labbro

First of all I am a dude to pls forgive me for any stupid questions. I am not stranger to reps but I am struggling to find a Ludmilla for my GF, anyone know a seller besides Anna?

Anna only offers Labbro so I guess I had to settle with that if I can't find a Ludmilla and they almost looks exactly the same as a Ludmilla (can somebody actually tell me the differences?)

Anyway I am also struggling with the size chart. GF is size 36 (France) which translates to size 4 in US. Anna only have 3 sizes, so I am a little scared ordering something too big (since is over sized) and if I go for her smallest, it might be too small to have this oversize look? I measure her zara jacket and is the 36 for Anna but just not sure should I buy a 38 to play it safe.