I feel like we know enough about Ling Biyu's situation to make some bad guess' about who she's likely to become. She's a Ling with another father than her sister which means she probably isn't as flighty and inattentive, but retains as version of Ling Qi and Qingge's fearful need for freedom, safety and friendship. She'll likely grow up in a rising clan with few peers where Ling Qi is stationed and the newly settled Ling territory, meaning she'll spend her time watching her burgeoning clan grow as her mother gets it in order and her sister work to improve it's fortune. I could see her looking up to her mother as the active head of their household and Ling Qi who'll impress on her a desire for achievement. She'll hope to be a stable, patient presence where her sister likely disappears for months on end on some quest or other.
Most importantly she has shown a connection to spirits in her dreams and dreamed of going to a river before Ling Qi brought her to one, so Dreaming and Hidden might be interested in her. I'm thinking a bit of a socialite making alliances and using spirits and dreams to play games of intrigue. Still very much like her sister only poised where Qi is skulking, preferring plans, traps, minions and drawn out fights of attrition followed by brutal executions. Extroverted with an endless energy for friends and allies against Qi is introverted nature.
{X} Talent 6. Reliable, safe.
{X} Lunar. You follow your sister's path. Slightly better starter arts as Ling Qi can provide her own. May feel like you're re-treading FoD.
{X} Musician.
--{X} Flute.
{X} Other. Write in.
--{X} Spear.
Ling Qi gave her Grinning's Jade Slip which she uses to dance around opponents like a shadow in mist.
{X} Bao Hai. Ling Qi desired you to try and form ties with him.