There is kinda a reason why most of the roster, both male and female, have champs rarely sporting appearances above the benchmark of being middle aged in 30s-40s or having the typical appearance of some frail and old person.
And it's not just Soraka and LB, Yi was thousands of years old in his old lores and he looks like he's in his late 20s. Xin has his lore spanning across 2 generations of Jarvan where he should probably be in his 50s at least by now, despite looking like he's still in his 20s, and Riot had to sorta fake it by later changing his hair to slightly grey from jet black to try and make him seem a little bit older but then he still looks and sounds far younger than his actual age. Then there is Braum, where depending on how you look at his bio/story he may be completely ancient or possibly immortal (he is AT LEAST 5 generations old) even though he looks like he's still in his 40s; and this is why there have been the fan theories suggesting that he may have been an Iceborn.
Youthful people look better, you know. This is why characters tend to look young, and even battle grandpas, a trope that's often used in certain medias, even though they're grandpas their body often looks like a fit man in his 30s or at least mostly not severely out of shape as old people typically are.
Though I agree, we can try adding more wrinkles and white hair onto female characters and whatnot, sure.
........
That said, I don't agree that much on Soraka. I mean, she's a goddess. Defamed, okay, but still a goddess, so she kinda gets to have eternal youth.