Petal is used as a term of endearment where I live so its sort of like calling a child darling or sweetheart for me, however I dont see it as being a no go, flower/ plant names are quite popular at the moment, I know girls called Blossom, Daisy, Fern, Fleur, Hazel, Heather, Holly / Hollie, Iris, Jasmine. Lily, Poppy, Posy, Rose / Rosie, Violet and Willow so why not Petal