Read this series in the 80's & can't recall titles or author though likely to be female author.
All I can recall of this sword & sorcery trilogy is that there was a female protagonist by the name of Soren or Sorren. Somehow she'd met up with man who ended up bringing her to his hidden community to train in martial arts/weaponry. The community was communal with people living in their own homes but working & training together.
For some reason, the title for the last book keeps coming to mind as "The Northern Shore" or something like, but googling that has turned up nothing that fits what I remember. The story ends in a final battle at a northern castle in winter & I seem to recall the "foe" had hordes of non-human creatures of some kind.