The item linked above does give "footnote" citations of some sources for the information; but they are "summarized" rather than quoted, which implies an "interpretation" has been made. As I am not really familiar with the site, I don't know that they have an established reputation for accuracy, or even what "purpose" the site was set up to accomplish.

The Daphne story is a well known one. I've found few "ancient" depictions of the legend, but it has been used by classic artists on a fairly regular basis. Poussin and Bernini examples date from about 1625. Maratti used it in 1681, Tiepolo 1745, Garellia in 1894, and Waterhouse in 1908.

Leighton did a 17 foot wide painting called "The Daphnephoria" in 1876 depicting a "rite of spring," possibly based on the story that certain Apollo cults made regular trips to "the source of the laurel" to bring back fresh laurel to their temple(s). There is an implied, but unconfirmed, presumption that "the source" of the laurel was where they believed it was created when Daphne was "transformed."

The prevalent use of the laurel as a "badge of honor" supports stories that have it given to the "virgins of Apollo," with the suggestion that a young man might so honor one in whom he had a particular interest - and perhaps hoped to transform into something other than a virgin. This specific use of the laurel is alluded to, but not directly described in any text I've found thus far. Whether it was actually a practice in Roman religion is academic, as the traditional belief that virgins were honored with the laurel would seem to be sufficient for reference to it in folk lore and music.

A "working translation" pending more authoritative information, would be that "I'll wear the laurel" means "you may worship (court?) me." Or perhaps even "I'll be your goddess?"

Gaia (or Gaea) does not figure prominently in the "epic" tales that are best preserved, but is a reasonable one to have transformed Daphne, and seems to be the one most reliably cited. Diana is currently a very "popular" diety, but had enough of her own troubles to be an unlikely power for that transformation. As an "equal" to Apollo, she would likely have faced terrible retribution, whereas Gaia was one of the "old order" forces much less affected by the whims of the "more active" dieties. One must suspect that the few sources who put Diana into this story have "modernized" the tale - which has been done frequently just to reduce the number of dieties that appear in old sources.

John