Upstairs loo

My bathroom is downstairs and I need a loo upstairs. I can't afford an en suite bathroom but think I could have just a loo and small basin in an alcove in my bedroom. I'd have some sort of screen there.
When I told my daughter she was absolutely horrified, as though I'd proposed a bath tub in the middle of the sitting room. Installing walls, ventilation, lighting would make the project impossible. Nobody's going to see or use it except me.
Are you all horrified too or is it feasible?