I agree with applestar. I have a mini rose bush that isn't even in the ground, it's in a big pot and it would be above your window sill. That's just too tiny a space for roses. If you tell us where you are located and what direction that window faces (when you are looking out of it), we could probably make a suggestion for dwarf shrubs you could use there.
The roses do look a little sickly, but we would could help more if we knew more about how they have been treated (weather, sun, fertilization, watering, any sprays, have you checked for insects, black spot, etc). Since next to a house isn't a full sun location, they should do better once moved into full sun.