When FonePaw Android Data Recovery analyzes your device, did you see the interface of "rooting failed" and you just click "Continue Scanning" but not "Advanced Root" (in the early version, it is called "Manually Root")? If yes, please choose "Advanced Root". Actually, the program will scan data in a more in-dept level after Android device rooting. Here is the guide to root Android:
Once you have rooted the device successfully, please use Root Checker to check the root result.
When the root is done but the program still shows zero data, your deleted data may be overwritten by other new data. Thus, before successful recovery, please stop using the device lest the lost data would be covered.