My daughters DSI we just bought used doesnt see her DS Lite game ICarly what could it be?

Help please - is it game compatibility everything I read says it shouldnt be an issue, is it the system if so wouldnt it give me an error it just doesnt show a game in slot? Help please very frustrated :(|||It's possible the cartridge might be corrupted or just broken i'd suggest going to where you bought the DSI and ask them to test the cartridge for you on another DS to see if that's the problem, if it still doesn't work than the cartridge is indeed broken and must be replaced with another copy.