Years ago, I called a cemetery to ask about the burial of my wife's aunt. After the lady who answered the phone gave me the information, she asked me if I wanted the details on the 5 other burials in the family plot. The others were all children or children-in-law of the aunt. I thanked her profusely for helping me.
Try and avoid asking about just one person when you contact the cemetery. Those buried in the same plot or set of lots frequently are relatives.