From my understanding and others, this is just a rumor. At this moment it's not confirmed that anyone owns the Dew Kiss Flower itself - but a replica of a flower that looks exactly like the Dew Kiss Flower as it has the same sprite! This flower is called a White Flower. In which it is obtained during, "What a Foolish Quest - Mission 1"....
Mission 1 - First Mission
When Bozo tells you to cut a White Flower
from the White Flower Temple
), head to the south gate of Thais. From there, keep heading south until you reach a river. Then, go around the river and head further south until you see the small building. Cut one of the flowers there. When you try to cut a wrong flower, the following message appears:
This flower is too pathetic. When you cut the correct flower the following message appears: The stubborn flower has ruined your knife but at least you got it.
You see a white flower. It weighs 0.10 oz.
Rumored to be from a floor reset in Oramond, however not confirmed. I did leave a comment asking to clarify the item in question.
Tibian Thread here also discussing if this item is possible to obtain, commentors also wrote it is from the first missions of "What a Foolish Quest"