Hello Solveigh,
I also really like your floor plan. No wonder, it is very similar to our house, which we built 14 years ago.
However, we have 3 kids' rooms upstairs. Your library is my study.
I would like to share a few brief notes with you from our experience:
Galleries in the children's rooms: these were no longer used as sleeping areas just a few months after moving in, but rather as play or workspaces. Our children wanted to be able to see the sky or the garden when falling asleep and waking up and moved their beds back to the lower area. Plan for each bed space to be 1.40 m wide. Sooner or later this may be necessary.
It is also relatively warm upstairs in our house. We also did not plan any skylights. Today I would make a shed roof and illuminate the galleries through north-facing windows – that would also be nice for ventilation on warm days.
Consider placing the study on the wall of your bedroom to create a noise buffer from the children. We sleep wall to wall with our now 17-year-old son. Neither he nor we find that particularly pleasant.
Otherwise, I am looking forward to your further planning. It will definitely be a beautiful house!
Best regards...