The Guest Cottage: A Novel - Nancy Thayer
I received this book in exchange for 
an honest review from NetGalley.
Sophie Anderson has been a supportive wife to her husband Zack for sixteen years.  Her husband's life revolves around his work as an architect, while Sophie is focused on raising their two children, fifteen year old Jonah and ten year old Lacey.
Zack doesn't call to tell Sophie he'll be late for dinner so she decides to check his schedule on his computer.  What she finds is a memo 'Remember L's bday.'  She guesses it's his secretary's birthday.  But then she sees the memo for the next day, 'Discuss Div with S.'
When her husband returns home she decides to confront him about the second memo and this is how she finds out her husband wants a divorce.  She's shocked and confused and tells her husband that a college friend had phoned the day before checking to see if they'd want to rent her family's summer home in Nantucket in July and August.  Sophie is hoping Zack will come with them to work on their marriage.  Zack refuses and says he won't pay for it.  Sophie decides she will use her inheritance from her Aunt Fancy to take her and the children to the cottage for the summer.
Trevor Black owns his own software company and is a widow with a four year old son named Leo who is having a difficult time coping with his mother's death and showing obsessive behaviors.  Trevor consults with a phychologist and the doctor suggests a vacation; somewhere Leo had never been with his mother.  Coincidentally, one of Trevor's old college friends calls him with an offer to rent his family's summer home for July and August and he accepts because it is just what the doctor has ordered.
As you may have guessed, Sophie and Trevor both head to Nantucket and need to work out the situation between them both renting the guest cottage for the summer.
Sophie's children grow close with Leo, Sophie finds a beau in one of her daughter's new friends in the area and Trevor fights his attraction to Sophie.
This is a light, flowing read; perfect for summer.