Hanalei Bay Resort is a wonderful vacation spot for families with children, and avid golf and tennis players!
Large main swimming pool with separation of adult and children's areas, and a large, rock surrounded hot tub with a sand bottom. Semi-private beach is easily accessed by foot or resort-provided golf cart shuttle. Eight tennis courts on property and resort is located right on Hole #3 of the Makai Golf Course (I often walked to the Makai Clubhouse right from the resort).
There are other beaches within walking distance, or from a short but circuitous car ride. The town of Hanalei is only a short 10 minute drive down Highway 560, and further down the same road provides quick access to the famed Ke'e snorkeling beach and the Napali Coast's Kalalau trailhead.
Plenty of local restaurants nearby and a grocery store at the entrance to Princeville.