so big thonk time
I dont think kaisas symbiotic voidling would survive being separated from her, despite the lurking concern that it might eat her in the back of her mind
her lore clearly states that she stabbed its heart and broke her knife trying to pull it out while it bonded to her arm
the lore never specifically states that said knifeblade actually got removed, since it can be assumed that the knife broke while it was still impaled into the creature
and also having a ruptured heart would probably just hurt your chances of living independant of your partner in general