A 60 sqm eat-in kitchen
but that simply won’t be in the floor plan, since there also has to be a staircase, a proper child-friendly entrance area with suitable storage space, and a guest WC.
And the ground floor without the room behind the garage is just under 50 sqm ... minus the stair area (at least 6 sqm with access area), hallway and entrance (rather 4 to 5 sqm), so there are about 40 sqm left for eating/living/cooking. And in my opinion, the pure guest WC without shower also belongs there,
Although I don’t really find the gallery that desirable either .. I’m just not a gallery type ;). I would actually put the parents’ bedroom with shower bath, an office (rather small), and living/TV/reading room (as large as possible) on the first floor. And then on the attic floor three equivalent rooms plus a bathroom with bathtub, possibly a bathtub/shower bathroom.
That way you’re prepared for 1, 2 or 3 children (a second child could also be twins ;) ) or for 2 children and a real guest room or 2 children and possibly a second office, because suddenly both parents work from home.
Day-to-day life with small children will certainly mostly take place in the eat-in kitchen, which for the toddler phase can also offer enough play space .. always nicely combined with the garden. Additional toys then only in the children’s rooms.