That lens is not discontinued. Its one of Canon's best selling prime lenses for lowlight use. When you refer to the other cheap lens she has - could it by any chance be the 50mm F1.8? Also - do you know which camera body she has? If I know that, then I can tell you if its full frame or crop sensor. For example - if its a crop sensor then the 85mm will probably be a bit long. What type of photography does she normally do (or want to do)? If I know that, then I can help suggest the most useful lenses.