As far as I know, Maria was not very politically involved. First, her mother-in-law who hated Paul made sure they were kept out of it. Second, her husband Paul was only Tsar for a few years before he was murdered and thus she couldn't do a lot in those years. Third, after Paul was murdered, I think she retreated and spent most of her time bringing up her younger children (mikail, nicholas and anna).
She was a serious, intelligent and artistic. She left her artistic marks in Pavlovsk.