It's almost become a thing of the past now... But yes, it used to be common practice for cameras and lenses to get a Clean/Lube/Adjust (CLA) every year or two, maybe three depending upon usage. Today people tend to "upgrade" so often that it's become a pretty rare service.
Modern DSLRs do have fewer moving parts and are pretty close to "lifetime" lubricated. Modern cameras may need less attention, but meters can drift out of adjustement, moving parts wear with a lot of use, and lubrication can dry out and moving parts might become sluggish. Rather than servicing and repairing a part such as a shutter, today if it's far enough out of calibration the modular unit the might be entirely replaced instead.
Info on cleaning the camera's sensor
. Read it thoroughly, done wrong there are opportunities to do serious damage to a camera during cleaning, that might mean an expensive repair. Or, take the camera in and have the sensor cleaned, if you are concerned about cleaning it yourself.
Exterior lens cleaning is actually pretty similar to sensor cleaning, though usually with slightly different products.
In addition, with lenses you might want to inspect inside with a flashlight to be sure there isn't a lot of dust or, worse, fungus starting to grow in there. If there is, it needs to be checked by a technician at a repair facility.
Also, if your daugther is noticing degradation of prints, or even just the images on computer screen... is her computer regularly calibrated? Here's an article about callibration
. (Note: laptop computers are difficult to calibrate because the viewing angle often changes, as well as the ambient light environment.)
Calibration is actually done throughout the workflow process. The printer needs to be clean and fully functional, and driven by a "profile" that matches it and the specific supplies (ink and paper) used with it. Softwares used in the course of processing need to be set to matching profiles, and the right color space and file type need to be produced for the intended purpose of the image.