"Bit part" is far too grandiose a term for Scend Wavegift's astonishingly brief appearance on stage in Fatal Revenant, the penultimate book in The Third Chronicles of Thomas Covenant. She is by far the most anonymous of Rime Coldspray's group of Swordmainnir - so much so that she isn't given a single line of dialogue. Furthermore, she also dies off stage, so is even denied the opportunity to utter "Gaak!", "Aargh!" or "Glurp!" as she kicks the bucket.
Honestly - what does SRD have against this most sketchily depicted of giantesses? Even the mysterious Three-Winged Bird of the First Chronicles gets more screen time than this poor red-shirted extra. The latest man-made highly radioactive elements with half-lives in the merest nanoseconds seem positively durable, compared to Scend Wavegift.
If more evidence of authorial apathy were needed, we don't even learn Scend Wavegift's name until after Lostson Longwrath has snapped her neck during one of his innumerable escapes from the shackles purchased by the giants from the Bhrathairain. Now okay, I know the giants have little love for or experience of metalwork, but you'd think they'd have realized by now that they got stiffed by the untrustworthy folk of the Sandhold and got sold a pair of joke handcuffs... hence why Longwrath is a veritable and incessant Houdini. Anyhow, as all Chronicles scholars know, you don't go to Bhrathairealm if you're after effective bondage gear. Nope, instead have a word with the nearest wedge of ur-viles - those guys can create the most fiendish of manacles that'll shackle anybody.
Role in the Third Chronicles
Basically, to get killed. Oh, and to cause Latebirth to feel guiltily responsible for the manner of her death.
None. Oh, I suppose her name is of some slight interest - "scend" is a word meaning "the push or surge created by a wave". Those giants sure do love all things briny and maritime, huh?