I would highly recommend you read 'A Place Of Secrets' by Rachel Hore.
Summary:
Set in London. For the past three years, Jude Gower has thrown herself into her work. Since the death of her husband, she has immersed herself in appraising for Beecham's auction house. For a while now, Jude has tried to build a relationship with a man named Kaspar, but her enthusiasm seems to be wavering. So when she takes a call from Starbrough Hall concerning a large family library of heirloom books, she warms to the task instantly. In addition to being a welcome diversion from the daily grind in London, a trip to the countryside might give her a chance to clear her head. Besides, Starbrough Hall is right in the middle of her childhood stomping grounds. Her sister, eight-year-old niece and gran all live in neighboring villages, giving her journey a dual purpose.
The Wickham family, owners of Starbrough Hall, embrace her presence, despite their sadness at having to give up their treasured library. They introduce Jude to their extensive collection of manuscripts and volumes on astronomy, along with several pieces of equipment from a long-dead ancestor. Hard times have made it necessary for them to sell off some of the property, including a tract with a tower on it that generations have called the folly. Its draw is irresistible, yet there remains an eerie aura about it. Nonetheless, there is no denying its wonderful position for stargazing. Its condition, though, can be treacherous.
As Jude catalogues the library, she becomes intrigued by a story she discovers about a young woman nobody in the family can quite explain.
"No one knew where Esther had come from - or where she went. Like a comet, there was just the brief bright glimpse of her life in her memoir, only for her to disappear once more into shadow."
After hours spent reading Esther's diary, Jude finds that she can't bear to leave her story unfinished. She dives in with renewed energy.
Meanwhile, Claire, Jude's sister, is worried about her daughter Summer's dreams. They might be evidence of a serious disorder, or they might simply be night terrors. Either way, Summer has been having some very restless nights. The dreams seem to have started right about the time a friend, Euan, took Summer to see the folly. Could there be a link? Odd, too, is the fact that the dreams sound strangely like the ones Jude herself has had.
Starbrough Hall has many secrets on the estate, not just the ones surrounding the folly. Even Jude's gran has harbored one for many long years. Claire has covered up bits of her past. And whose bones were those found near the folly? As Jude searches for the answers to these mysteries, she might find herself unexpectedly falling in love.
Honestly, it's one of those books you just can't put down. I'm halfway through another of Rachel Hore's novels, 'The Glass Painter's Daughter' and I love it aswell!