On the Nautiloid she recruits Lae'Zel, then when it crashes to the ground, Lae'zel gets captured by some Tieflings.
That's how it is for every playthrough. Unless you play as Lae'Zel.
The fight with the 2 intellect devourers comes before you can get to Lae'zel's cage. It's on a corridor you have to pass on the way to Astarion, Gale and Lae'zel.
You can just run past them for the most part. The biggest issue with playing as Shadowheart is her stats aren't the best and she always tends to miss her hits.
