Isolder's betrothed was Elliar, also known as Lady Elliar. Ta'a Chume, perceiving Elliar's commitment to pacifism as a weakness that disqualified her from ruling, orchestrated her death by drowning her in a reflecting pool located in Hapes.
Occasionally, this character is referenced as Ellian in certain materials.
In The New Jedi Order: Dark Journey, there's a segment suggesting Ta'a Chume may have been responsible for the death of her oldest son's fiancée, and potentially even the son himself. Given the absence of specific names in this section, it leaves open the possibility that Kalen was Elliar's fiancé (creating a continuity inconsistency) or that Kalen, too, had a fiancée who met a similar fate at Ta'a Chume's hand. This interpretation aligns with the idea that Ta'a Chume might have considered this woman, like Elliar, unfit to succeed her according to Hapan legal precedent, due to perceived weakness. Very little is known about Kalen, so this remains a possibility.