Don't understand this joke? Can someone explain?

This is a very interesting joke, and the following is the translation:

A mother took her daughter to visit her mother-in-law. When the car passed the cemetery, the little girl turned around, saw something and asked her mother, "Mom, will the cemetery bury two people in the same place?"

"Of course not, dear," mom replied. "Why do you think so?"

Because I just saw a tombstone that said,' A lawyer and an honest man died here'.

A foreigner's tombstone is to engrave his title before his death on the tombstone, just like China's: Father of XXX.