Players will need to find another vessel to vent out their never-ending hate towards Gale.
Players in Baldur's Gate 3 will no longer be able to permanently destroy dead characters by yeeting them into a chasm, as a recent update has changed this mechanic.
She is captured by some tieflings not too far down the road from Asterion and Gale. I think there may be another fork you can go down the main path with, so it might be possible to miss her. I'm in Act II first play through and am playing slowly enough that that was about a month ago, so it's a little fuzzy.
Apparently I totally missed Asterion. I'm about to leave the underdark and I don't recall ever running into him. Is he a rogue? My party is sorely lacking a rogue.
Use the quick travel thing to go back to the beach at the beginning of the game. He's right in the crashed ship region, so if you missed him, just fill out some map there. You should run into him.
I missed both her and Gale in my first playthrough and while Gale never appeared anywhere else, Lae'zel does show up a bit later. Albeit kind of randomly.
There's a conversation that pretty much plays out as if you had her the entire time, then afterwards you have the whole "hey wait you were on the ship too" thing and she can join you.
I never found her at the start, but randomly found her body in a cave somewhere near the end of act 2 I think it was. Never had the chance to talk to her after leaving the ship in the beginning.
I guess that happens if you also miss the second possible encounter.
Very Minor Spoiler
For me Lae'zel was in the north with the Voss and the other Githyanki near the mountain pass entrance past the inn. The place with the cutscene where the dragon destroys the bridge. I can see how you could miss it if you went to Act 2 through Grymforge and never went to the Mountain Pass, or came back to it later and time already passed.