Julia Quinn's To Sir Philip, with Love.
6th book in the Bridgerton Series
It started with a letter and ended with a letter, this Bridgerton book is the story of Eloise, a Spinster and Sir Philip, the widower and two twins that at first would do everything in their power to chase people away only wanting the attention of their father who instead spent his time in his greenhouse with his plants. Being a Bontist it was much easier caring for the plants then his own children even after his wife Marina (cousin to Eloise) decided to take her life by the lake on the grounds only to be rescued and dying days later. He grew a wall around him and only Eloise's letters to him got thru to him.
He asked her to meet him after a year of letters... and she actually appeared at his door. I actually think this story is the most heart warming story. It made me care about them so much. I smiled when they were happy, teared up when things were going sour. It seems to me that these books are getting so much better... btw Love them all so far!