Name : Starswirl (Yes, i know this is a very popular but they both enjoy him so i was thinking it could be a nice detail)

Nickname: Starry, Cinnamon roll (Because of her hair), Grumpy

Identity: Female, still discovering herself (she/her)

Family : Twilight Sparkle and Moondancer (mother's), Andromeda (young sister)

Personality: Asocial and realistic, Starswirl personality is basically a copy of her mother's old days, she is very stressed and hates to interact with other creatures, like a nerd that does ''hisss'' for interaction, she can try to be very calm and patient but this is ruined if you annoy her too much, very smart and knows very well how to deal with dangerous situations

Bio : Starswirl was born in Canterlot, everypony was so happy about it! Expecting some really friendly and special personality for her, considerating she was the daughter of Twilight Sparkle, the princes of friendship! They were all crushed noticing how shy and scared she was in the filly time, always in the eye of ponies and forced to be more interactive, and even getting bullied for that, she gave up, making herself sure that would crash the dreams of expectations that the ponies had for her
In her teenager times, she became way more antisocial, showing how much she hated the interaction and friendship with other filly's of her age, becoming even violent sometimes, usually was in the library of Moondancer reading and making homework, Twilight was worried, she felt herself guilty for making her daughter act like this, tries to fix it until the nowadays, but it's too late, she is basically her mother old personality, and probably there is nothing that they could try

Special talent : Basically something like a attorney? I can't define her talent but she has something with the sense of justice (yes, she screams OBJECTION!, no, you don't make the rules here)