Think in terms of living areas. On the ground floor, you have 3 living areas and one functional area:
[*]Cooking & Eating [*]Sleeping & Spa [*]Relaxing & Media [*]Entrance & Wardrobe & Stairs & WC
Distribute these living areas according to your property and their orientation to each other. I am thinking of an entrance directly into a large room (60+ sqm), in which wardrobe, cooking, eating and the stairs are combined yet clearly structured. The stairs in this room lead to a gallery that extends across the entire length of the room; in the middle of it, a hallway branches off to the upstairs rooms, which are located above the sleeping and living areas. The enormous air volume keeps the room constantly fresh, acoustic elements prevent it from becoming "echoey." Now you have life at the front of the house and the connection to the children's living area upstairs. The more private part is also on the ground floor, accessible in an age-appropriate way and protected from everyday noise.