Smoke
Across many human cultures and many thousands of years, burning to create smoke as part of a ceremony, especially funerals, was and still is believed to carry prayers and wishes as souls were and are perceived to leave the body at death like smoke. Even today, the burning of incense in religious ceremonies carries on the practice.
I have no idea whether the ancient meaning was consciously part of Cindy's request, but it may be appropriate to regard it so, whatever one's beliefs may be.