Spring's birth was heralded by dreams, foretelling the birth of a new favored one of Selune. She was to be the new Silver Wolf (Mist Greycastle was the first Silver Wolf). She has an odd birthmark: a purple disk on her right cheek.
In 1386, the Chosen of Shar decreed that 1387 would be the Year of the Sable Wolfstone according to the Black Chronology. 1387 was the Year of the Emerald Ermine, the Emerald Ermine beings a giant emerald that could turn into a green weasel. The Sable Wolfstone was the corrupted version of the Emerald Ermine--the change had to be effected by dipping the Emerald into the blood of the Silver Wolf. Since Mist Greycastle was a bit hard to kidnap, the Sharrans took Spring captive instead.
Spring was eventually sent back to her family through a series of negotiations between Elandan and Vashti's army, the Greycastles, and the Sharrans, but not until after the ritual had been completed. Spring seems to have recovered, though there are some who think it 'fated' her in some way.