hey! I've seen a lot of people on twitter and tumblr saying that today is lena's birthday, do you know where that comes from? was it said on the show and i missed it or something?
A lot of people think of today as Lena's birthday (including me) because October, 24th 1993 is the date on her arrest report, back from Luthors, which also matches with the "20 years ago" from the same episode, where we met 4 year old Lena.
This was published in this book called "The secret files or Kara Danvers" that is supposed to be a guide to the TV show. I'm not sure how canon it's supposed to be, if at all, but it has a lot of little things like this about the episodes and some characters!
So, yeah. Some people don't think of it as canon and some do. It doesn't really matter, it's all just for fun! I personally love it, so happy birthday Lena!