My family spent 2 weeks in Vietnam, it was a great trip as the tour was well designed for family, we and our children enjoyed very much, the highlights were cruising Halong Bay, of course, Hoian, beautiful white beach in Nhatragn, and the peaceful countryside in Mekong delta. I really recommend it. Here is the itinerary you can refer: https://www.bestpricevn.com/Tour_Beach-vacations-in-Vietnam-14-days.html