when i had to make a choice i choose to rest, and apparently patience was the right call

but i still feel bad because of what happened to Calisca (I know it was her fault for being impatient, but still)

was there a way to avoid it beside listening to her bad advice? and will I find her sister later now that she's gone?

Yes, if Heodan doesn't get injured during the fight and the following scripted interaction then he doesn't need to rest - which avoids the whole situation.

But minor spoiler:

It doesn't really matter whether she dies from the traps or not.

Next minor spoiler:

You can indeed find her sister later.

Edited April 13Apr 13 by Boeroer