The CW has announced that Talia al Ghul will be making her first appearance on Arrow this season, starting with episode 10 with further appearances in later episodes.
Actress Lexa Doig will be taking on this role of Ra’s al Ghul’s other daughter. Doig is a Canadian actress of Filipino-Scottish-Irish ancestry with past roles including the titular role of Andromeda, and one episode roles on CW shows Smallville and Supernatural.
https://www.youtube.com/watch?v=2xnWVbgBDsk
The al Ghul family is nothing new to Oliver Queen and the rest of Team Arrow. The Emerald Archer has already defeated Ra’s al Ghul back in season 3 (2015), technically still married to his daughter/Talia’s older sister Nyssa.
Described as worldly and cultured, Talia is an elite warrior who doesn’t pick sides but rather creates her own.
This is not the first live-action portrayal of Talia al Ghul, Marion Cotillard played her in 2012’s The Dark Knight Rises. It has not been made clear if she’ll be a complete villain like her father on Arrow, or if she’ll play the occasional hero role like Nyssa has been. Let’s just hope the writers of Arrow don’t plan on carrying out further BatmanPlot-bending and having her intent on having Oliver’s child who would probably (shouldn’t be) named Damian.