She was present in the volume 2 finale where there were plenty of Boarbatusks, Grimm Eclipse which is a canon form of media has Weiss as a playable character and Boarbatusks as a fairly common enemy. She was at the battle of Beacon where also lots of Boarbatusks were present. RWBY is a show where ever since volume one there's been plenty of days and all kinds of events that happen off screen.
1. in the Volume 2 finale, Boarbatusk were only seen running after the train inside the tunnels. They never made it into the city and did not see any combat.
2. Boarbatusk were present *after* the Battle of Beacon, they infiltrated the city after the major fighting was done.
2. Grimm Eclipse's storyline is indeed a canon form of media when it comes to the story. But whether which Team Member fought in what area is entirely up to you, as a player. It might aswell be Ruby who solo'd the entire storyline for that matter if you played Single Player.