Just for fun, comparing Vocaloids' character ages to the ages of other characters in other franchises. I'll be doing it with my Vocaloids (that have canon ages, so no Gumi as she's kinda...vaguely in her teens).
Disney Princesses:
Hatsune Miku (16): Aurora, Ariel, Merida, Mulan, Moana
AVANNA (18): Rapunzel, Anna (in Frozen 1), Pocahontas, Raya
Other (major commercial, so the list isn't too long) Vocal Synths:
Hatsune Miku:
Vocaloid: Tone Rion, CUL, Xin Hua, Yuezheng Ling, Xingchen/Stardust, IA
SynthV: Stardust again (lol), Koharu Rikka (possibly, as high school starts in 10th grade in Japan and she's said to be a second-year), AiKO
CeVIO/VoiSona: IA again, Satou Sasara, Kanato Mell
AVANNA:
Vocaloid: Yuzuki Yukari, anon/kanon, UNI, (Taiwanese) Prima
SynthV: Cangqiong
CeVIO/VoiSona: MYK-IV, Kizaki Airi
Disney Princesses:
Hatsune Miku (16): Aurora, Ariel, Merida, Mulan, Moana
AVANNA (18): Rapunzel, Anna (in Frozen 1), Pocahontas, Raya
Other (major commercial, so the list isn't too long) Vocal Synths:
Hatsune Miku:
Vocaloid: Tone Rion, CUL, Xin Hua, Yuezheng Ling, Xingchen/Stardust, IA
SynthV: Stardust again (lol), Koharu Rikka (possibly, as high school starts in 10th grade in Japan and she's said to be a second-year), AiKO
CeVIO/VoiSona: IA again, Satou Sasara, Kanato Mell
AVANNA:
Vocaloid: Yuzuki Yukari, anon/kanon, UNI, (Taiwanese) Prima
SynthV: Cangqiong
CeVIO/VoiSona: MYK-IV, Kizaki Airi