What can be done to help osgood schlatter disease for a 14 year old and quick?

Ice,rest: No magic answer if you have inflammation related to is good schlatters you need to avoid the offending activity first then i would use ice message and nsaids usually things calm down in 1-2weeks.

Reduce activity: The issue with osd is use activity. When it flares up, anti-inflammatory medications can help some but the main treatment is to reduce stress on the knees by reducing activity. In RAE cases a soft long leg brace is used to relax the muscles & their pull against the inflames area.