How do I bathroom / kitchen / extension? etc.

This your nursery? Looks great!

I think this looks like a lovely and calm nursery space. No doubt there are some classily illustrated (but bollocks) picture books on the shelf on the right and some wooden animal toy ornaments too. Allow the pre baby nesting perfection.

We only ever painted our kids rooms white, which quickly became drawn-on and grease/poo/bogey smeared.

Beyond 2yrs the plastic tat starts to build and before you know it the floor is 75% lego, there are rotting forgotten snacks under the bed, you have given them wardrobes they won't use and the walls are covered in stickers and blue-tacked magazine posters.

Each to their own but its the overly 'curated' older kids rooms you see on the renno accounts that annoy me more.
Because they are clearly driven by mummy / daddy for their blog rather than what the kid actually wants. 10 yo (IME) do not give a fuck about seasonal shelf displays or muted scandi chic.