Oi dont ya put Helenium on the Loli pot or I´ll go all Clint Eastwood on you !
Really now, if you wanna go all "loli here loli there", study up on what "loli" actually means for crying out loud.
Same with Dianthus. Dianthus and Helenium are NOT lolis.
They are teens at best sure, but you can clearly tell them being adults, and the way the art is done in FKG its rather easy to tell. that they are most definitely not lolis. Borderline lolis ? Well... maybe subjectively on man to man basis maybe.
You know what, I´ll do ya a big one, here watch this - you might now this guy, you might now, but he does explain it in rather "user friendly" way: https://www.youtube.com/watch?v=UP80nZOPk88

Edit: And yeah Helenium is pretty neat, both her personality and her H-scene, to her quotes and adorable crybaby attitude. She is a waifu material for sure and you wont regret if you pick her up (I at least did not, thats for sure). She pretty much took the N1 place from Mei on my list