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.
A direct confirmation is sensible before committing money or changing a travel plan.