What would bother me about the plan is that you basically have your back to the door when standing at the washbasin. But from your answers, I can tell that you're not really looking for suggestions, but more for confirmation. Personally, such a bathroom in a new building would be way too small for me, but as is well known, man's will is his paradise...
Even though I think the tip is wasted: have you considered placing the washbasin next to the shower? That way, the person entering the bathroom won't run into the back of the person brushing their teeth (especially children are often quite energetic).