When a gently born spinster has little money, her choices are few. She might receive an offer of marriage, but it's unlikely to be from a wealthy man, so she'll have a hard life trying to make ends meet for her growing family.
I wouldn't like to live in a castle now, but I'd enjoy a visit to Restormel in Cornwall in its 13th century prime. It's a circular castle with the rooms built against the outer walls and quite intimate in size. Life there wouldn't follow the pattern of more classic castle design.