When CW's newest comic book television series Legends of Tomorrow was announced, people were excited. When promo images were revealed and Sara Lance was hanging out as the new White Canary, people were confused, since Lance was dead. A bit of light has been shed on all of this and according to E!, Marc Guggenheim revealed that Sara Lance will be returning prior to the newest CW comic book series Legends of Tomorrow debuts.
The White Canary will be launched in the first few episodes of Arrow... 4x08, our typical crossover episode, will be doing a lot of heavy-lifting in terms of getting the Legends of Tomorrow characters set up and also seeing where they are with relation to The Flash. It's a big episode.
It seems like we'll be getting to see the resurrection of the character before LoT starts, which makes sense because we don't want LoT to spend a ton of time explaining everyone's backstories.
See Sara Lance return on Arrow in episode 8 of season 4. Arrow returns to CW for its 4th season on October 7 at 8/7C.