Although far from the text-wringing of her more experimental works (her short stories or 'To The Lighthouse') this is still Virginia Woolf and in accordance requires a certain focus.
In classic epic family drama style, the narrative revisits members of the same family throughout a period ranging from 1880 to "present day' (the book was published in 1937).
In classic Woolf style, it doesn't follow fluid narrative with clearly defined focalizer characters, but rather pounces on various family members at seemingly haphazard moments of their lives, keeping the reader on his/her toes, continually guessing through whose eyes we are now seeing, feeling and thinking.
Brilliant, of course! Albeit a tad exhausting.