Based off this post
Canon until 205
For most of her life, Lena’s soul marks were nothing less than very confusing.
Lena was four when names formed on either wrist, written in dark ink. It was two weeks after she’d been adopted, and the marks added to the horror of everything changing and the peace of everything coming together that was rushing through her even as a child. Her adopted brother Lex had grinned without reading the names and given her a high five that somehow meant the world.
Scrawled across her right wrist in a curling, slightly rushed font, was the name Kara Danvers. This was confusing, if only for the first 16 years of her life. For years she wondered why another girl’s name would be on her wrist? She couldn’t be her soulmate? This Kara Danvers was destined to be her enemy, right? Then Lena was 17 and Rebecca Lewis took her to see a bad movie and they held hands and kissed softly at the end of the evening and everything became easier.
Well not everything.
Because of the other name on her other wrist in neat, simple writing.
Who the hell was Supergirl?