Hi Nelly: You can try curtains or that cling type paper in a frost, or, maybe some plants would do. Please let us know where the windows are, how tall and what type of privacy you want, and we can help you a bit more. Good luck
Curtians, window films, foux stained glass. Blinds, roller shades. Take your pick.
Windows can be covered with sheer curtains for daytime privacy and shades for night. We use the plastic film you can add to windows for our bathroom windows. It allows sunlight to come in, but is not transparent. It comes in designs and colors too or just plain , what ever you prefer. Here is one i chose for you that is on a door with decorations: https://www.hometalk.com/39287626/ez-stain-glass-windows
Target sells the window film online in several patterns.