While the Goodreads title and other places claim this a part of the Hometown Heartbreakers series, there is absolutely no tie to that series with the possible exception that it also takes place somewhere in Northern California, although not Glenwood.
I usually don't do synopsis, but apparently the publisher didn't write one.
One day Erin Ridgeway shows up at Parker's door and says this is your 4 year old daughter by my twin sister Stacey who died from birth complications. Christie looks so much like Parker that he doesn't question it. Erin has become Christie's mommy but knows she needs her dad and so they begin to work out a plan for joint custody. For starters, they will spend a couple weeks in his huge house with him. Kiki, his housekeeper will be an unofficial chaperone for the adults, for all the good that does. The two weeks turns into a whole summer.
Christie is precocious and endearing. Erin is a generous and brave single mom. She doesn't ask for money. She just wants Christie to have a dad. Parker falls in love quickly with his daughter. Parker is not a bad guy and probably his worst fault is blaming himself for way too many things.
Erin's backstory is not too sad other than the loss of her sister and Erin's life as a single mom.
Parker's backstory is slowly revealed. It involves the death of his wife, whom he loved, and a one night stand with Stacey, but even when fully revealed they don't add much.
That's pretty much it. There is some humor and the two leads dance around their feelings for each other. There is one brief bit of excitement, but even that is not earth-shaking. The charm of the book is in the relationships and dialog. It's not bad, but it lacks any depth. It's also a quick read.
Mature themes: there is no violence, but there are a couple of explicit love scenes.