The title explains it all. Here are my ideas for voice lines:
"Grenade! Get out of there!" (triggered when a enemy throws a Frag Grenade, Thermite Grenade, Arc Star, or Nox Gas Grenade at Wraith)
"Behind you!" (triggered when a enemy is within 25m of Wraith behind her, suggested because it was featured in the Voidwalker trailer)
"Enemy Death Totem activated! Be careful!" (triggered when a enemy squad with a Revenant uses his Death Totem within 30m of Wraith)
"The drone sees you. Shoot it down." (triggered when a Crypto Drone is within 30m of Wraith, before it can scan her)
"Enemy Bombardment on your position! Get out of there!" (triggered when Gibraltar or Bangalore uses their ultimate while Wraith is in the radius of the Ultimate)
"Enemy Portal nearby. Don't let them sneak up on you." (triggered when a enemy Wraith portal is within 25m of the Wraith)
"They opened the Vault. Stop them." (triggered when a enemy squad opens the Vault when Wraith is nearby)
Source: https://www.reddit.com/r/apexlegends/comments/hghx4i/ideas_for_wraith_2_more_voicelines_for_her/