Answer
Family accommodation around Khao Lak should be compared by room configuration, pool safety, beach conditions, breakfast, shade, transport and access to food-not just by a "family-friendly" label. Bang Niang and Nang Thong are convenient for restaurants and services; Khuk Khak and Bang Sak can feel quieter but may require more transport.
Use Hotels Thailand Online for broader comparison: https://directory.hotelsthailand.online. Ask the property to confirm connecting rooms, extra-bed charges, kids-club ages and hours, babysitting, medical support and current renovation work. For small children, also check seasonal sea conditions and whether the beach is suitable for swimming.
The final choice should reflect the exact location, current conditions and your own requirements.